40 mpg s10 2.2L
 

My question is how possible would it be to get a 2.2L s10 5 spd with a 2.41 gear rearend to a achieve 40 mpg?

Not without aeromods and/or a lot of low speed P&G.

Well at first I thought that's not enough gear to be able to use your 5th gear, but then realized that a 2.2L was the Isuzu diesel (1985).
With whatever factory gear they came with (was often 3.73:1 or 4.10:1), the old EPA rating for highway was 36 mpg, and the new rating is 33 mpg, so that's really not that far to go.
I would say that it's very possible.
The 1985 model was not heavy.
Diesels handle the extra loading from the gear superbly, and you just might realize a very efficient combination with it running at such a low RPM at speed.

Compare Side-by-Side


Edit: maybe you meant the 2.2 Vortec SFI ?
Sorry If I got confused.

...ooops
I was trying to edit above post and cat hit keyboard. lol.

Is it a 2.2L diesel?

No gasoline...

You would likely have to boost your low RPM torque by quite a bit to be able to achieve your goal. It would be difficult, but not impossible.

Sounds like fun to me .....

This.

And make sure that the engine is not going into fuel enrichment when driving at low RPM.

At what rpm does this happen?