ShaneM

Lol, my car came with 3.73's, i must have a lead foot. the best i ever got before the blower was 21 on the highway, typically it wa 15 mpg in the city. I racked up a 14 mpg in the city with the blower.

SirKnightTG

I've been all about 3.73 for a long time, but for a while now I've been thinking 4.10 with my auto. The reason is that the RPM difference between them and 3.73 is not that much and I live in central Texas (near Austin) in an area called "The Hill Country" because of how freaking hilly it is. When I'm on the highway, I'm pretty much constantly going up and down hills, many that are quite steep. My 3.31s hate this. So I figure because of the hilly terrain where I am, 4.10 might be a better choice. Plus they're fine for the city. If this area was more flat, like in east Texas 3.73 would be the thing to get. Of course, 3.73 would work damn fine in this area too I'm sure. But under the circumstances, I just don't see 4.10s really hurting me any over 3.73.

The biggest issue is getting them installed by someone who knows their **** that won't charge a kidney and left nut like the dealer. My dealer is a FRPP dealer that can do the job well, but my quote the last time I was there was like $700. Which, if that include the parts too I guess that's 400-500 labor there.

6+6 Stang

Just drove 800 miles from NC to MS wanted to try Chevron cuz don;t have in NC by me, I use Shell so 3.73's 5 Spd got 27 all way that was doing 70+ and back seat full and trunk full about 300 extra Lbs, I get 23 in town

Larry1014

I must have a lead foot. I get about 24 MPG on highway and most time about 16 on town unless I keep my foot in it all the time. Have gotten as low as 14 doing that.

Driver72

I agree with what others have said, you'll probably lose 1-2 mpg on the highway, but stay the same or slightly better in city (why? cuz with shorter gearing, you won't get on the gas as hard to accelerate ahead of traffic. You'll therefore short shift more and get to the higher gears easier. You can also start easier in 2nd, or do a 1st to 3rd shift

jasezero

I have 3.73's as well...best I've pulled is about 20 highway...usually i get about 15-16 city though.

cidsamuth

I just took an 8.5 hour trip to Virginia from Michigan last weekend.

With my 4.10s and the Tillman 93 All Out Tune (JLT CAI and Steeda Delete Plugs), I got 24.5 on the way there. This was cruising at 75 MPH and on hilly terrain most of the way. I even ran the air conditioning for the last half of the trip.

On the way back, I put the Tillman 93 Road Race Tune in, which is less aggressive (and I assume less lean). I only got 22.8 MPG that time, and I didn't run the air conditioning. I'm sure other things factored in besides the tune, like the general elevation change and the weather conditions.

SirKnightTG

I think the adaptive learning stuff gets reset when you load a new tune b/c I have always noticed a little worse MPG after loading a tune. But after a few days or a week it goes back up to where it was.

cidsamuth

Yea, maybe. Though the All Out tune was freshly loaded before the original trip.

MrSandman

Have you tried turning "overdrive" (5th gear) off by pressing the button on the shifter? It helps a lot with hills.. and feels better with city driving. I leave OD off until I hit 60 mph no matter where I am.