Fuel compositions

Distillate fuel for indirect injection compression ignition engines containing at least the combination of (i) organic nitrate ignition accelerator, and (ii) an alkoxysilane having the formula:

• R.sub.n Si(OR').sub.4-n
• wherein R is hydrogen or alkyl having from 1 to about 12 carbon atoms per alkyl group, R' is alkyl having from 1 to about 8 carbon atoms and n=1, 2 or 3, said combination being present in an amount sufficient to minimize coking in the nozzles of indirect injection compression ignition engines operated on such fuel.

A method of inhibiting coking on the injector nozzles of indirect injection compression ignition engines, which method comprises supplying said engine with a distillate fuel containing at least the combination of (i) organic nitrate ignition accelerator, and (ii) an alkoxysilane, said combination being present in an amount sufficient to minimize such coking in the engine operated on such fuel.

A method of inhibiting coking on the injector nozzles of indirect injection compression ignition engines, which method comprises supplying said engine with a distillate fuel containing at least the combination of (i) organic nitrate ignition accelerator, and (ii) an alkoxysilane having the formula:

• R.sub.n Si(OR').sub.4-n
• wherein R is hydrogen or alkyl having from 1 to about 12 carbon atoms per alkyl group, R' is alkyl having from 1 to about 8 carbon atoms and n=1, 2 or 3, said combination being present in an amount sufficient to minimize such coking in the engine operated on such fuel.

An additive fluid concentrate for use in distillate fuels containing at least the combination of (i) organic nitrate ignition accelerator, and (ii) an alkoxysilane, said combination being present in an amount sufficient to minimize the coking characteristics of such fuel, especially throttling nozzle coking in the prechambers or swirl chambers of indirect injection compression ignition engines operated on such fuel.

An additive fluid concentrate for use in distillate fuels containing at least the combination of (i) organic nitrate ignition accelerator, and (ii) an alkoxysilane having the formula:

• R.sub.n Si(OR').sub.4-n
• wherein R is hydrogen or alkyl having from 1 to about 12 carbon atoms per alkyl group, R' is alkyl having from 1 to about 8 carbon atoms and n=1, 2 or 3, said combination being present in an amount sufficient to minimize the coking characteristics of such fuel, especially throttling nozzle coking in the prechambers or swirl chambers of indirect injection compression ignition engines operated on such fuel.

An additive fluid concentrate comprising about 5 to 95% by weight of a mixture of octyl nitrates and from about 5 to 95% by weight of tetramethoxysilane.

An additive fluid concentrate comprising about 5 to 95% by weight of a mixture of octyl nitrates and from about 5 to 95% by weight of tetraethoxysilane.