I own a 1988 toyota 4 runner with a 22re engine running a auto trans with 31x10.50 tire only getting 12 miles to a gallon what can i look for new o2 senser plug wires and cap also new checked timing and it was ok would a set of 4;10 gear help changing from 3;73</P>

 

NO! going to steeper gears will make it much worse. increased gearing means steadily higher RPMs, which means more fuel usage!

 

yes i know steeper gears means less fuel milage but the gearing could bring the power range back into what it should be sence it has 31x10.50 tire insted of 225/15 tires

 

i would look to increase the power by means of things that wouldnt bring the R's up so high if its mileage youre worried about

 

does it feel like your engine also lacks power? maybye check your cylinder compression to see if your rings or pistons are excessively worn. oil consumption is usually the indicator. 22r's are anemic but also very thrifty engines. check your intake manifold for leaks too. i had an84 toy with 33's inflated to a little over max psi when i was on pavement, and it helped with mileage quite a bit.