Abstract: A fuel testing data acquisition system calibrator, signal simulator, and pickup complementary apparatus.

Abstract: A method of assigning an octane number to a sample fuel based on the knock intensities obtained from a plurality of reference fuels each having a different assigned octane number while operating an engine at an established compression ratio. The knock intensities obtained from the plurality of reference fuels are plotted relative to the assigned octane numbers of the fuels. A line is fit to the plotted knock intensities. The octane number for a sample fuel is assigned based on the knock intensity obtained for the sample fuel, the knock intensity obtained from a prototype fuel having an assigned octane number, and the fitted line. In embodiments, an R squared value is obtained for the fitted line and compared with a minimum acceptable R squared value and the fitted line is validated if the R squared value is at least the minimum acceptable R squared value.

Abstract: A fuel injector interface device and associated method include an interface device having a plurality of input leads and a plurality of output leads. The input leads are communicatively linked to the fuel pressure sensor on the common rail of a vehicle fuel injection system. The output leads are communicatively linked to a display device such as a diagnostic scope. Circuitry positioned within the interface device detects the rail pressure signals, filters the signals, and outputs data to the display device representing a graphical depiction of the same. A method of using the interface device includes generating the signals, mapping the signals to an individual fuel injector of the vehicle's engine cylinder and determining fluctuations in the strength of the displayed signals to determine anomalies in a particular fuel injector.

Abstract: A method provides for operating an engine configured to use a plurality of differing fuels. The method includes determining a fuel combustion ratio of the plurality of differing fuels associated with at least one engine cylinder of the engine based at least in part on one or more of a plurality of characteristic profiles. This maintains one or more of a plurality of actual values associated with usage of the plurality of differing fuels relative to defined corresponding threshold values. The fuel combustion ratio includes a ratio of the plurality of differing fuels to be delivered to the at least one engine cylinder. A fuel delivery system delivers the plurality of differing fuels to the at least one engine cylinder based on the fuel combustion ratio.

Abstract: A portable, compact, real-time and accurate sensor and method for deriving a physicochemical property of a liquid fuel, such as cetane number, carbon content, carbon/hydrogen (C/H) atomic ratio, or heating value (net heat of combustion). The sensor comprises a constant-volume ignition chamber equipped for measuring ignition delay and magnitude of a peak rise in pressure or temperature following dispensation of a liquid fuel into the chamber. The sensor utilizes air at atmospheric pressure and microliter quantities of fuel. The sensor can be implemented in real-time refinery operations for blending diesel fuels that meet government mandated cetane number standards as well as in applications for standardizing jet, biodiesel, and synthetic fuels, which presently are not classified by any physicochemical property.

Abstract: A portable fuel synthesizer, comprising a portable housing, an electrical power source utilizing the hydrocarbon gas as fuel and connected to the portable housing, a boiler utilizing the hydrocarbon gas as fuel and connected to the portable housing, a reactor connected to the boiler to react the hydrocarbon gas to the hydrocarbon liquid, the reactor connected to the portable housing, at least one temperature sensor connected to the reactor to sense at least one temperature of the reaction, at least one pressure sensor connected to the reactor to sense at least one pressure of the reaction and a control system controlling the at least one of at least one temperature of the reaction and the at least one pressure of the reaction, the control system connected to the portable housing.

Abstract: Explosion test systems for determining explosibility indicies (Kst) of certain dust and gaseous fuels are provided. The test systems comprise a combustion vessel (130) and associated control equipment (110) containing software for operating the combustion vessel and collecting data generated thereby. The combustion vessel (130) generally comprises a test chamber (140) and a reservoir module (150) operable to inject a fuel into the test chamber, wherein an ignition module (170) ignites the fuel.

Abstract: In order to estimate the cetane number of a fuel, fuel injection is executed by controlling the driving of a fuel injection valve by a prescribed amount. The amount of change in the rotation of a diesel engine generated in response to the fuel injection is detected, and the cetane number of the fuel is estimated on the basis of this amount of change in the rotation. The actual amount of fuel injected from the fuel injection valve is detected, and when the difference between the amount actually detected and the prescribed amount is equal to or greater than a threshold value, the execution of the fuel cetane number estimation process is restricted.

Abstract: A method provides for operating an engine configured to use a plurality of differing fuels. The method includes determining a fuel combustion ratio of the plurality of the fuels associated with at least one engine cylinder of the engine based at least in part on one or more of a plurality of characteristic profiles. This maintains one or more of a plurality of actual values associated with usage of the plurality of fuels relative to defined corresponding threshold values. The fuel combustion ratio includes a ratio of the plurality of fuels to be delivered to the at least one engine cylinder. A fuel delivery system delivers the plurality of fuels to the at least one engine cylinder based on the fuel combustion ratio.

Abstract: A fuel composition having a boiling range of between 95 to 440 degrees Fahrenheit wherein the fuel composition has (a) a total sum of n-paraffins and naphthenes content of at least 7 volume percent.

Abstract: A value of ignition delay and a value of a flame spread rate are measured with respect to fuel which is an object to be determined. When the measured value of the ignition delay falls within a range which is smaller than a reference line and constitutes a first range or falls within a range which is larger than a reference line and constitutes the first range, goodness or badness of quality of fuel is determined based on goodness or badness of quality of fuel which is decided in accordance with the first range. When the measured value of ignition delay falls within a range between the reference line and a reference line which constitutes a second range, goodness or badness of quality of fuel is determined based on whether or not a measured value of a flame spread rate falls within a good product range.

Abstract: A cetane number estimation apparatus injects fuel from a fuel injection valve in a diesel engine based on a target fuel injection amount, calculates an indicator of output torque of the diesel engine produced through fuel injection, and estimates the cetane number of the fuel using the calculated indicator. The cetane number estimation apparatus includes a pressure sensor for detecting fuel pressure varied by variation in actual fuel pressure in the fuel injection valve at the time of the fuel injection. The cetane number estimation apparatus also has a pressure correcting section that is adapted to calculate actual operating characteristics of the fuel injection valve based on a variation waveform of the detected fuel pressure and corrects the target fuel injection amount based on the difference between the calculated actual operating characteristics and prescribed reference operating characteristics.

Abstract: A fuel property determining apparatus is provided that can reduce power consumption in energization of a fuel property sensor by efficiently determining a fuel property as determined by activating the fuel property sensor. Upon starting an internal combustion engine, it is determined whether or not determination is made of the fuel property in a preceding trip. When the fuel property is determined in the preceding trip, a switch is turned ON to activate the fuel property sensor after waiting for a short period of time after the start of the internal combustion engine. When the fuel property is not determined in the preceding trip, the switch is turned ON to activate the fuel property sensor immediately after the start of the internal combustion engine.

Abstract: A method and a system is disclosed for determining RON and/or MON values from constant volume combustion chamber apparatuses capable of producing pressure versus time combustion profiles having a fast combustion region and a slow combustion region, where data from the two regions is used to compute RON and/or MON values for light distillate fluid samples using a series expansion equation.

Abstract: Methods and systems for selectively fuelling a vehicle are provided. One example method of fuelling a vehicle may include receiving a fuel in a fuel reservoir in the vehicle, and directing the fuel to one of a plurality of storage tanks based on a fuel type. In one example, the directing of fuel may include adjusting one or more fuelling valves positioned between the fuel reservoir and the plurality of storage tanks to vary a direction of fuel flow to the plurality of storage tanks.

Abstract: The fuel physical property determination method relating to the first aspect of the present invention includes: a test fuel flame-imaging step of obtaining imaging data by imaging flames formed by supplying a pre-mixed gas containing a test fuel and an oxidant agent, to a test tube in which an internal flow path thereof has a diameter set smaller than a flame-quenching distance at normal temperature; and a physical property determination step of determining a physical property of the test fuel by comparing the imaging data obtained in the test fuel flame-imaging step and imaging data obtained by imaging flames ignited by supplying a pre-mixed gas containing a standard-mixed fuel and an oxidant agent, to the test tube, the standard-mixed fuel having a known physical property.

Abstract: A method for detecting the blending level of biodiesel fuel in an internal combustion engine includes setting at least two post injection fuel quantity reference values respectively for known biodiesel blending percentage levels. A post injection fuel quantity value is evaluated and is compared with the at least two post injection fuel quantity reference value. A predetermined correlation set of values between the post injection fuel quantity value and a biodiesel blending level expressed by biodiesel percentage with respect to the petro-diesel is used to determine the biodiesel blending level.

Abstract: A method recognizes at least one feature of fuel in an internal-combustion engine (1). The method comprises steps of: detecting, by at least one sensor, intensity (S) of vibrations generated by the internal-combustion engine (1) within a measurement-time window; determining a value of at least one synthetic index (I) by processing the intensity (S) of the vibrations generated by the internal-combustion engine (1) within the measurement-time window; comparing a synthetic index (I) with at least one predetermined comparison quantity (TH); and recognizing the feature of the fuel as a function of the comparison between the synthetic index (I) and comparison quantity (TH).

Abstract: A cetane number detection device for an internal combustion engine includes: fuel injection devices that injects fuel individually into cylinders; control device that executes injection of fuel from at least one of the fuel injection devices at a predetermined injection timing when the internal combustion engine is started; combustion determination device; and detection device. The combustion state determination device determines whether the state of combustion in the combustion chamber of at least one cylinder into which fuel is injected by the at least one fuel injection device is an ignition state or a misfire state. The detection device detects the cetane number of the fuel on the basis of the state of combustion in the combustion chamber.

Abstract: A method for determining the ignitability of a fuel, in particular a self-igniting fuel, based on the ignition delay of the fuel during the combustion in a test engine. According to the invention, the ignition delay is determined from the combustion curve and/or the heat curve.

Abstract: An object of the present invention is to provide a gas turbine control device which is capable of performing correction on the basis of a fuel composition of fuel gas to be supplied to a gas turbine, and is capable of changing an amount of correction in response to variation with time of the gas turbine. To attain this, a frequency analyzing unit 25 performs a frequency analysis of combustion oscillation of a combustor and splits a result of the analysis into respective frequency bands. Then, a state grasping unit 22 checks an operating state of the gas turbine on the basis of the result of the analysis of the combustion oscillation and process value of the gas turbine, and corrects the checked operating state on the basis of a fuel composition or a heat capacity of fuel gas measured by a fuel characteristic measuring unit 200. A countermeasure determining unit 23 conducts a countermeasure for controlling an operating action of the gas turbine on the basis of the operating state thus checked.

Abstract: In a gas-mixture-nonuniformity acquisition apparatus for an internal combustion engine, the nonuniformity of fuel concentration within a gas mixture is acquired under the assumption that, in a process in which a cylinder interior gas taken into a combustion chamber of the engine and fuel injected into the combustion chamber mix together to form a gas mixture, a collision reaction repeatedly takes place within the gas mixture in such a manner that, due to collision of two gas volumes having different fuel mass ratios, respective portions of the two gas volumes mix together, and the mixed portions separate from the corresponding gas volumes and form a portion or the entirety of another gas volume having a fuel mass ratio different from those of the two gas volumes.

Abstract: A cetane number estimation method is provided in which: the preliminary injection is preformed multiple times at different compression end temperatures with a fuel tank (26) containing fuel having a predetermined cetane number, and an engine torque increase caused by each preliminary injection is calculated and the relation between the compression end temperatures at the respective preliminary injections and the engine torque increases caused by the respective preliminary injections is determined; the compression end temperature and the engine torque increase at a predetermined reference point on the relation are recorded as a basic compression eng temperature and a basic engine toque increase; the preliminary injection is performed at the basic compression end temperature and an engine torque increase caused by this preliminary injection is calculated; and the cetane number of fuel is estimated based on the relation between the calculated engine torque increase and the basic engine torque increase.

Abstract: A minute amount of fuel is injected into a combustion chamber during fuel cut, and a cylinder pressure is detected when the minute amount of fuel is being combusted. Then a combustion ratio is calculated based on the detected cylinder pressure, and a determination crank angle, which is used for determining a cetane number based on the combustion ratio, is determined. The cetane number is determined based on the determination crank angle.

Abstract: A cetane number estimating device (1) comprises cylinders which are provided to an internal combustion engine where a part of the exhaust gas can be fed back from the exhaust system to the intake system, injection device (30) for injecting fuel into the cylinders, measuring device (40) for measuring the ignition timings in the cylinders, and estimating device (20) for estimating the cetane number of the fuel according to the measured ignition timing as well as any one of a first correlation between the ignition timing corresponding to the stage at which when one cylinder is in the intake stroke, another cylinder in the exhaust stroke exhausts non-burned gas and the cetane number and a second correlation between the ignition timing corresponding to the stage at which when one cylinder is in the intake stroke, another cylinder exhausts burned gas and the cetane number.

Abstract: A fuel compensation factor (FCF) is determined to account for the amount of oxygenated fuel blended in diesel fuel. In one embodiment, the FCF is based on an expected exhaust gas oxygen concentration compared to an actual exhaust gas oxygen concentration. The FCF is used to estimate an amount of oxygenated fuel in the blend. Such estimate can be used to adjust the exhaust temperature model, which is used at least in determining the temperature in aftertreatment devices, the fuel dilution model which affects oil change recommendations, and the diesel particulate filter loading model which affects regenerations. Biodiesels are more prone to waxing at lower temperatures. The estimated amount of biodiesel and the temperature in the injection system are used to prevent and/or delay starting when it is predicted that too much wax exists in the fuel system.

Abstract: A fuel distillation property determining apparatus for use in a multi-injection system for diesel engines. The apparatus acquires a physical quantity indicating a state of burning of fuel in the diesel engine, determines a physical quantity variation sensitivity defined by a ratio of a quantity variation that is a difference between a first value of the physical quantity, as acquired upon execution of a first one of a sequence of sub-injections, and a second value of the physical quantity, as acquired upon execution of a following one of the sub-injections, to a difference between a first quantity of fuel sprayed in the first sub-injection and a second quantity of fuel sprayed in the following sub-injection, and determine a cetane value of the fuel based on a predefined relation between the physical quantity variation sensitivity and the cetane value. This ensures the accuracy in determining the cetane value at low costs.

Abstract: A fuel feed chamber and a residual fuel chamber that are connectable to each other via a shutoff valve are provided in a fuel tank. When the fuel tank is refueled, the fuel feed chamber and the residual fuel chamber, which have been connected to each other so far, are disconnected and then fuel is fed only into the fuel feed chamber to refuel the fuel tank. When the engine is restarted after the refueling, only the fuel in the residual fuel chamber is supplied to the engine while the fuel feed chamber and the residual fuel chamber remain disconnected from each other, and the engine is controlled in accordance with the property of the fuel in the residual fuel chamber, which has been determined in advance.

Abstract: A sensor for detecting and differentiating chemical analytes includes a microscale body having a first end and a second end and a surface between the ends for adsorbing a chemical analyte. The surface includes at least one conductive heating track for heating the chemical analyte and also a conductive response track, which is electrically isolated from the heating track, for producing a thermal response signal from the chemical analyte. The heating track is electrically connected with a voltage source and the response track is electrically connected with a signal recorder. The microscale body is restrained at the first end and the second end and is substantially isolated from its surroundings therebetween, thus having a bridge configuration.

Abstract: There is disclosed a fuel property detector for detecting a property of fuel injected by a fuel injector into a cylinder of an internal combustion engine. The fuel property detector includes an injection commander, a change detector, and a fuel property determiner. The injection commander commands the fuel injector to perform a fuel injection for fuel property detection into the cylinder of the engine. The change detector detects a change in the rotational speed of the engine which is caused by the fuel injection for fuel property detection. The fuel property determiner determines the property of the fuel based on the change in the rotational speed of the engine detected by the change detector.

Abstract: The invention concerns a method for determining the composition of a fuel mixture from a first and at least a second fuel for operating a combustion engine, whereby the fuel mixtures of different compositions require various air/fuel ratios to achieve a stoichiometric combustion. Thereby it is provided that the air volume that has been delivered to the combustion engine, the fuel quantity that has been delivered and the oxygen content in the exhaust gas of the combustion engine are determined during one or several stationary operating phases of the combustion engine during one or several measuring phases, and in that the composition of the fuel mixture is determined from these values. The procedure allows an accurate and reliable determination of the composition of a fuel mixture for combustion engines that are operated in flex-fuel-mode.

Abstract: A control system for an internal combustion engine, which is capable of estimating a property of fuel accurately even when the engine is in an operating condition other than idling. An in-cylinder pressure sensor detects an amount of change in pressure in a cylinder #1 of the engine as a pressure change amount. An ECU calculates an amount of heat released in the cylinder #1 as a heat release amount, according to the pressure change amount. A vehicle speed sensor, a crank angle sensor, and an accelerator pedal opening sensor detect load on the engine. The ECU estimates a cetane number of fuel based on the calculated heat release amount and the detected load on the engine.

Abstract: A control system for an internal combustion engine, which makes it possible to estimate a fuel property parameter indicative of a property of fuel in use, in a plurality of operation modes of the engine, respectively, to thereby increase the chances of estimation of the fuel property parameter, and select an appropriate one from the estimated fuel property parameters to thereby more appropriately control the engine. The fuel property parameter is estimated when the detected operating conditions of the engine correspond to any of a plurality of operation modes. Depending on a plurality of fuel property parameters estimated in respective operation modes, one of the fuel property parameters is determined as the fuel property parameter for control of the engine.

Abstract: A spark-ignition type internal combustion engine, including a main tank for storing a to-be-determined fuel having an unknown self-ignition property, an auxiliary tank for accumulating a reference fuel having a known self-ignition property, and a controller. The controller is programmed to supply to a combustion chamber a blended fuel prepared by blending the to-be-determined fuel and the reference fuel at a predetermined ratio, measure a self-ignition property of the blended fuel, and determine the unknown self-ignition property of the to-be-determined fuel based on the measured self-ignition property of the blended fuel, the known self-ignition property of the reference fuel and the ratio of the blended fuel. The controller is also programmed to introduce the to-be-determined fuel after the determination from the main tank to the auxiliary tank, and store the to-be-determined fuel in the auxiliary tank such that the to-be-determined fuel serves as a next reference fuel having a known self-ignition property.

Abstract: A fuel distillation property determining apparatus for use in a multi-injection system for diesel engines. The apparatus acquires a physical quantity indicating a state of burning of fuel in the diesel engine, determines a physical quantity variation sensitivity defined by a ratio of a quantity variation that is a difference between a first value of the physical quantity, as acquired upon execution of a first one of a sequence of sub-injections, and a second value of the physical quantity, as acquired upon execution of a following one of the sub-injections, to a difference between a first quantity of fuel sprayed in the first sub-injection and a second quantity of fuel sprayed in the following sub-injection, and determine a cetane value of the fuel based on a predefined relation between the physical quantity variation sensitivity and the cetane value. This ensures the accuracy in determining the cetane value at low costs.

Abstract: Operation of a DI HCCI engine is optimized for maximizing load capability and load ranges via matching fuel ignitability with the compression ratio of the engine.

Abstract: A method for determining fuel volatility and consequently performing cold starting of an internal combustion engine; in the event of cold starting, the method provides for the determination of an enrichment percentage as a function of a stored value for fuel volatility; the determination of a predicted value for starting quality before performing starting; the starting of the engine using the previously determined enrichment percentage; the determination of a measured value for starting quality; the determination of a correction value of the stored value for fuel volatility as a function of the comparison between the measured value for starting quality and the predicted value for starting quality; and the updating of the stored value for fuel volatility by applying the correction value to said stored value, so consequently modifying the amount of enrichment in force.

Abstract: When a combustion feedback correction coefficient to which a predetermined value is added in correspondence to half miss firing judgment exceeds a heavy fuel judgment value (K0), heavy fuel judgment is made, and heavy fuel corresponding control for increasing the fuel amount by a combustion feedback correction coefficient (Kfb) and by prolongation of increasing fuel amount (?) immediately after the startup is performed. When startup is consecutive startup, having a small drop width of a cooling water temperature (TH), from the last engine stop, and the number of times of ignition (Nig) accumulated during the last running is smaller than a warming judgment value (Nig0) at re-startup after running under the heavy fuel corresponding control, miss firing judgment is regarded as being impossible and alternative control for increasing the fuel amount is performed instead of the heavy fuel corresponding control.

Abstract: A method and a system is disclosed for determining cetane values from constant volume combustion chamber apparatuses capable of producing pressure versus time combustion profiles having a fast combustion region and a slow combustion region, where data from the two regions is used to compute cetane values for middle distillate fluid samples using a series expansion equation.

Abstract: An object of the present invention is to provide a technology that enables to determine the cetane number of fuel in a state in which it is actually used for running an internal combustion engine with an improved degree of accuracy. A fuel injection for cetane number determination in which a specified quantity of fuel is injected into a combustion chamber during a compression stroke or expansion stroke, is performed while the internal combustion engine is in a fuel cut state. The cetane number of the fuel is determined based on the time period from a specified time to a time of ignition at which the fuel injected by the fuel injection for cetane number determination is ignited.

Abstract: A fuel cetane determination device for an engine is disclosed. In one embodiment, the device comprises a controller that is arranged and configured to determine a rapidness of combustion based on a parameter relating to a combustion state of an engine. The controller is further arranged and configured to determine the cetane value of the fuel in use by the engine based on the rapidness of combustion from a correlation between the rapidness of combustion and the cetane value when the engine is in a first operating condition. The controller is further arranged and configured to determine the cetane value of the fuel in use by the engine based on the rapidness of combustion from a correlation between the rapidness of combustion and the cetane value when the engine is in a second operating condition. The correlation for the second operating condition has a different characteristic tendency from the correlation for the first operating condition. A method is also disclosed.

Abstract: A control system for an internal combustion engine that has at least one fuel injection valve for injecting fuel into a combustion chamber of the engine, and burns the injected fuel by compressing an air-fuel mixture in the combustion chamber. An operating condition of the engine and/or a refueling condition of a fuel tank for supplying fuel to the engine are/is detected. At least one operating parameter of the engine is changed when at least one of the engine operating condition and the refueling condition detected by the condition detecting means satisfies a predetermined condition in a predetermined low load operating condition of the engine. A cetane number of the fuel in use is estimated according to an ignition timing of the fuel detected after changing the at least one operating parameter of the engine.

Abstract: A system and method for monitoring tire pressure in a tire of a vehicle is described, in which a tire pressure reading in the tire and an ambient pressure reading are received, and a warning indicator visible to an operator of a vehicle is selectively activated based on the tire pressure reading, the ambient pressure reading, and a predetermined threshold. In one embodiment, the ambient pressure is used by an engine control system for regulating the air-fuel intake, transmitted to a communications bus, and used by a tire pressure monitoring subsystem configured for receiving the ambient pressure reading from the communications bus.

Abstract: A system is described using a fuel quality sensor for controlling various aspects of engine operation. In particular, an acoustic wave sensor is utilized to measure viscosity and density of gasoline fuels. This measurement is utilized to predict engine combustion quality during an engine start. Based on the prediction, the method adjusts engine operating parameters (such as fuel injection amount and ignition timing) to achieve improved vehicle driveability and engine combustion.

Abstract: A method and system for controlling both the pressure and temperature at the engine air intake, engine crankcase, and at the engine exhaust so that pressure and temperature conditions are equilibrated. Engines are tested both at simulated high altitudes (operating air at barometric pressures lower than the local barometric pressure at the test site) and low altitudes (operating air at barometric pressure higher than the local barometer at the test site) and at a variety of operating air temperatures. The method and system provide for the balancing of air pressure at the engine air intake and crankcase and engine exhaust. The effect of unbalanced air pressure is on engine emission test results is demonstrated.

Abstract: An engine system has an engine control module for controlling a ratio of air and fuel supplied to an engine. The engine control module controls the ratio of air and fuel in relation to a fuel parameter related to the specific energy of the fuel or the stoichiometry of the combustion reaction. The fuel parameter is updated in relation to the engine's performance.

Abstract: A fuel property determination system for an internal combustion engine is arranged to determine a fuel property indicative that fuel in use is heavy or light, on the basis of a degree of change of a revolution speed during a period from an expansion stroke of a first fuel injection cylinder at engine start to an expansion stroke of a final fuel injection cylinder in a first round as to all cylinders of the engine.

Abstract: A fuel property determination system for an internal combustion engine is comprised of a specific gravity detecting section which detects a specific gravity of fuel used in the engine and a fuel property detecting section which detects at least one of a cetane number, an octane number, an evaporation point, a heat of consumption and an aromatics content as a fuel property, on the basis of the specific gravity.

Abstract: Method for processing a sensor signal of a knocking sensor for an internal combustion engine, having the following steps: a time window is defined for the evaluation of the sensor signal as a function of the operating state and/or the operating behavior of the internal combustion engine, a plurality of sampled values of the sensor signal are sampled within the predefined time window with a predefined sampling frequency, and an output signal which represents the knocking behavior of the internal combustion engine is determined from the sampled values, the Fourier transform of the sampled values being calculated in order to determine the output signal.

Abstract: A method for determining the type of fuel used by a vehicle includes receiving hydrocarbon speciation and nitrogen-oxygen compound data from an emissions sensor. The hydrocarbon speciation data is compared to one or more hydrocarbon threshold levels, and each threshold level corresponds to an anticipated fuel type. The nitrogen-oxygen compound data is compared to one or more nitrogen-oxygen compound threshold levels, and each threshold level corresponds to an anticipated fuel type. Based on the comparison of the hydrocarbon speciation and nitrogen-oxygen compound data to threshold levels, an anticipated fuel type is determined.