What kind of mileage do you get?

[96-1500]

Hey guys, in terms of mileage, would it be worthwhile to go from my 3.42s to 3.73s or 4.11s with my 31"s? She's a torqu monster in first and second gear, 3rd she's a slug, and I rarely see 4th.

Depends on city or highway. If you drive over 50-55 mph on a regular basis, definitely not.

My 4.10s kill me on the highway. Honestly I don't think my highway mileage is any better than start/stop city driving (not that I'm in that situation often, but sometimes).

I know your truck is different in many ways, but lower gears mean more revs at speed.

 

[jdyates]

I stay in the city most of the time. It is incredibly rare that I drive highway or anything over 55mph (highest speed limit around here).

 

[96-1500]

I stay in the city most of the time. It is incredibly rare that I drive highway or anything over 55mph (highest speed limit around here).

In that case, it probably wouldn't hurt any to go to 3.73 or 4.10. My gears are great for that kind of stuff. My 3.42s in my old truck took a lot more umph to get them rolling. Great on the highway though!

 

[5spd Z71]

I've got the 3.42's in my truck, and in the city, there ok. Although it sucks cause sometimes your at the speed where you either lug it around it rev the piss out of it. Far from ideal. On the highway though, I turn 1500rpm's at 55mph.

If you only drive in the city, is go with the 4.10's. but then again I've never truck a truck with 3.73's. for some reason all 3 of our trucks have 3.42 gearing. I dunno how that worked out...


Sent from my iPhone in some random spot of Texas.

 

[satxwy]

I have 3.42s with 31s. I would stick with that. It works great for me, still seems to have plenty of off the line grunt. Occassionally around town at 40-50 I'll leave it in 3 instead of D just to stay more in the sweet spot of the RPM range. Highway I can get 17 mpg pretty easily, and city I'll get 14-15. I can run in 3 on the highway and only be at about 2700 RPM. Now that's a sweet spot.

If you think it's luggy once it's in 3rd/4th, just leave it in 3 so it doesn't shift up and put you at super low RPMs. That would solve the problem you seem to be having.

 

[dowsewashere]

I have 3.42s with 31s. I would stick with that. It works great for me, still seems to have plenty of off the line grunt. Occassionally around town at 40-50 I'll leave it in 3 instead of D just to stay more in the sweet spot of the RPM range. Highway I can get 17 mpg pretty easily, and city I'll get 14-15. I can run in 3 on the highway and only be at about 2700 RPM. Now that's a sweet spot.

If you think it's luggy once it's in 3rd/4th, just leave it in 3 so it doesn't shift up and put you at super low RPMs. That would solve the problem you seem to be having.

Since when is High RPMs = Better MPGs

 

[satxwy]

Since when is High RPMs = Better MPGs

That's why he wouldn't want to go 4.11s with 31s. 3.42s pull 31s around just fine. Switching to 3.73s for city mileage wouldn't really be worth the cost.

He said its a torque monster in 1st and 2nd, but seems to lack power in third and fourth. In my exp with 31s and 3.42s, that comes from the RPMs being too low around 45-50 mph. So keeping it in 3rd would keep his RPMs just under 2k instead of 1200, putting it in a much better spot in the power band.

 

[Michael D]

After getting my carb all sorted out, I've been getting pretty routinely 14 or more now. Not bad I guess, for using corn that is about $3.09 by me right now.

 

[96Z71ECSB]

Crap! 12.6 mpg this 130 mile trip with 400lbs in the bed one way and empty coming back. Of course, I did push the truck hard. I was approaching triple digits in a few spots.
I installed a Jet 180 degree thermostat along with a Hypertech power tune (Yeah,yeah. I know. Don't flame me) before I made the trip. The temp outside was around 18 degrees when I started the trip, 50 degrees coming back.
I did not like the thermostat. It took too long to heat up the cab. The tune was nice. It gave my truck a bit more low/mid/wide open throttle power.
I took the tune out yesterday and went back to a 195 degree thermostat. I'll report back next week.

 

[Vortec Lover]

17.09 MPG this last tank

Eat your heart out boys