Abstract: Lead-free, high-octane gasolines are made up of a selected class of C.sub.5 -paraffinic and C.sub.6 -hydrocarbons and a methyl-t-butylether compound (MTBE) such that they have specified physical properties of research octane numbers, Reid vapor pressures, densities at 15.degree. C. and sulfur contents and also have blended specified amounts of the MTBE compound and of those hydrocarbons to satisfy the requirements as determined by several specified equations. Startability of a cold automobile engine is conspicuously improved and emission of NOx reduced.

Abstract: A specified gasoline capable of maintaining a high octane number and reducing the amount of NOx to be contained in exhaust gases when consumed, which comprises as essential components(A) 3-30 vol. % of methyl-t.-butyl ether and(B) 1-15 vol. % of light straight-run naphtha with the balance being a base gasoline, the amounts of the components (A) and (B) being each based on the amount of the specified gasoline.

Abstract: A method of pre-heating feed water for boilers is disclosed which utilizes the exchange of heat between the tube side of a heat-exchanger which contains de-salinated and de-ionized water and the shell side which contains hydrocarbon vapors boiling in the range of 90.degree. to 150.degree. C. The tubes are made of carbon steel with their outer surfaces aluminized.