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bpmcgee · 11-03-2003, 05:10 PM

I'm not sure that I can agree that putting numerically lower gears in would help. My understanding is that this might help, but may also hurt if you end up bogging the engine down too much.

In these big trucks, everything I read suggests that the i6 and the v8 got just about the SAME mileage because the 6 had to work so much harder to hump the truck down the road. Because of this, I think that putting 3.08s in might actually hurt because the 6 would have a really hard time.

My understanding is that the way to improve MPG is to do things which improve the efficiency of the engine. HEI, as you suggest, free flowing air filters, and possibly headers come to mind.

Also remember that simple things like EGR and PCV valves can affect mileage as well. Make sure they're working right!

Brian

11-03-2003, 05:10 PM	#5
bpmcgee Registered User Join Date: Mar 2003 Location: Northern Illinois Posts: 2,181	I'm not sure that I can agree that putting numerically lower gears in would help. My understanding is that this might help, but may also hurt if you end up bogging the engine down too much. In these big trucks, everything I read suggests that the i6 and the v8 got just about the SAME mileage because the 6 had to work so much harder to hump the truck down the road. Because of this, I think that putting 3.08s in might actually hurt because the 6 would have a really hard time. My understanding is that the way to improve MPG is to do things which improve the efficiency of the engine. HEI, as you suggest, free flowing air filters, and possibly headers come to mind. Also remember that simple things like EGR and PCV valves can affect mileage as well. Make sure they're working right! Brian