[big gear head]

26 MPG isn't bad for S10. The 205/75/15 isn't real tall. I agree that trying a taller tire would be a good idea to see if the 2.2 can handle it. Your speedometer will be off, but I think you already know that. S10 rear ends are not expensive and there are a lot of them with the 3.42 gears. If you decide to go ahead with this then look around for a GU6 code 2 wheel drive rear end and swap the complete assembly.

[wildwind3962]

Will that also throw the speedo off and will I have to flash the computer I am thinking yes. Also the GU6 would be the 3:42 correct and the GU5 would be the 3:73? Is the 3:42 a better option as far a maybe upping the mileage 2-3 mpg?

[big gear head]

GU5 is a 3.23, GU6 is 3.42 and GT4 is 3.73. Changing from 4.10 to 3.73 isn't going to be much of a change. The 3.42 is very popular and works pretty well in most cases. Don't plan on towing anything or hauling much with the 3.42. I doubt that the 2.2 is going to have enough torque to pull a load like that.
Calculators
Play with this and try some tire sizes and gear ratios and see what you come up with.

[wildwind3962]

Originally Posted by big gear head

GU5 is a 3.23, GU6 is 3.42 and GT4 is 3.73. Changing from 4.10 to 3.73 isn't going to be much of a change. The 3.42 is very popular and works pretty well in most cases. Don't plan on towing anything or hauling much with the 3.42. I doubt that the 2.2 is going to have enough torque to pull a load like that.
Calculators
Play with this and try some tire sizes and gear ratios and see what you come up with.

Thanks a million Buddy I really appreciate all your input

[RWENUTS]

You won't be happy with 3.42 gears. With your little motor you'll be running in 4th or third and rarely in overdrive 5th.
What type of country you live in? Flat roads no hills you might get by. But any hills will kill your mileage.
Best cheapest way to gain your 2-3 mpg is just drive slower.

[wildwind3962]

Does it make a difference if it is a 6 cly or a 4 cly. I live in Illinois so it is mainly flat land not too many big hills too speak of although their are a few. Will the 3:73 save me any mileage at all versus the 4:10 stock that I have now?

[RWENUTS]

If you want to see the difference that different gears make then put on some taller tires. Some tire 4" taller than yours will drop your rpm to 2500. Some 265 75 15's will do the trick.
And it does make a difference whether 4 or 6 cylinder. Torque of the 6 is higher. Will pull a taller gear better.

[AutoGear]

An old trick is to install a vacuum gauge in your cab. Accelerate from a stop and watch the vac gauge. If the vac drops significantly, you're accelerating too quickly for efficiency's sake. This is a VERY old idea, thats been revamped with GPS and other sensors as a 'Driving Coach'.

You can also try things like: taller, narrower tires; different oils, high flow catalytic converter and mandrel bent pipe; the proper ignition system, not using your A/C and ditching things like the spare tire and A/C parts for lighter overall weight. These will produce gains (most likely small)

If you spend a significant time on the highway; 65mph is probably best. Some googling might produce Airdams for aerodynamics (not downforce). Conventional wisdom says tonneau cover, but there was some tests done on a TV show that an open bed on a truck actually creates a 'bubble' that helps the airflow coming off the roof of the truck. This will probably be more for your amusement than money saved.