Am I getting better mileage with 3.73's???

[Qwk88LX]

I recently had 3.73's installed in my car (+rebuilt trac-lock, new bearings..). I had 3.27's before & I got about 150mi/ tank Now my odometer is reading 160 & I still have an 1/8 of a tank left. So my question is, am I really getting better mileage or is my odometer off since the gears? I have 295/50/15's in the back..I used to get 240mi/ tank on my stock motor. I can only imagine what it'll be like in a few weeks when I install my C4..

 

[ECU5.0]

probably the mileage is off unless you put a new speedo gear in there....but im not sure if that would really do it

 

[Qwk88LX]

probably the mileage is off unless you put a new speedo gear in there....but im not sure if that would really do it

I did put the 23 tooth speedo gear in....

 

[Ambizzy]

Your odometer is off - you gotta change the speedometer gearing too =) Cheap process though (assuming you haven't done this yet from the 'increase' in mileage).

~Amber

//edit
Whoops, I waited to long to reply to your first post, so this one doesn't really help much anymore!

 

[Qwk88LX]

Your odometer is off - you gotta change the speedometer gearing too =) Cheap process though (assuming you haven't done this yet from the 'increase' in mileage).

~Amber

//edit
Whoops, I waited to long to reply to your first post, so this one doesn't really help much anymore!

Yeah, I actually counted the teeth on the speedo gear coz I didn't want it to be off..so I have no idea.

 

[Gearbanger 101]

It's actually possible that you might be getting slightly better mileage if you're doing a lot of it in town. Although the difference wouldn't be as dramatic going from 3.27's instead of 2.73's.

 

[Ambizzy]

Yeah that's true, if you're not doing as much highway driving then your mileage would increase a bit, but I wouldn't think it'd increase THAT much... hopefully someone else will have a bright idea =)

 

[Qwk88LX]

It's actually possible that you might be getting slightly better mileage if you're doing a lot of it in town. Although the difference wouldn't be as dramatic going from 3.27's instead of 2.73's.

Yeah, 95% of my driving is city/town..I still beat on it from time to time ..no complaints, just trying to figure out the logic of it

 

[Gearbanger 101]

Well, since you've got to a numerically lower gear. It should take a little less "omph" of the go peddal to get things moving from a stop. That combined with the fact that you're now able to run around in 5th gear on the strait aways, without bogging the engine may help you out in the mileage department. But like I said, it won't be as dramatic going from 3.27's as it would going from 2.73's.

Even after the speedo gear change, you're not going to be dead on. 3.55's are normally about as high as you're going to be able to compensate for with just a speedo gear change. Anything beyond a 3.55 ratio tends to still read a little higher and it only gets worse, the lower (numerically) you go.

 

[Qwk88LX]

Well, since you've got to a numerically lower gear. It should take a little less "omph" of the go peddal to get things moving from a stop. That combined with the fact that you're now able to run around in 5th gear on the strait aways, without bogging the engine may help you out in the mileage department. But like I said, it won't be as dramatic going from 3.27's as it would going from 2.73's.

Even after the speedo gear change, you're not going to be dead on. 3.55's are normally about as high as you're going to be able to compensate for with just a speedo gear change. Anything beyond a 3.55 ratio tends to still read a little higher and it only gets worse, the lower (numerically) you go.

I guess that kinda makes sense except that it's presently an AOD car with a tight converter..I'll be installing a fully manual C4 w/ reverse valve body & 2800 stall in 3 weeks so I wont have over drive anymore but hopefully my mileage wont be as bad as I had thought..hell I might end up going with 4.10's depending on what RPM's she goes through the traps at the track

 

[Gearbanger 101]

Ah well, that's what I get for not reading your list of mods, but it's still working on the same basic principal. But....yeah....a C4 is going to kill your mileage. If you want to see how it's going to be, drive around with your AOD in 3rd for a week or two. It's the same 1:1 ratio.

 

[ninety15.0]

I just had 3.73's installed in my car and rebuilt the rear end, and i am also getting better milage. It does make sense to me that if it takes less pedal effort to get the car going from a stop and keep it going without downshifting that you will indeed get better gas milage. Its not just you man!! lata

 

[Qwk88LX]

Ah well, that's what I get for not reading your list of mods, but it's still working on the same basic principal. But....yeah....a C4 is going to kill your mileage. If you want to see how it's going to be, drive around with your AOD in 3rd for a week or two. It's the same 1:1 ratio.

lol..yeah, It'll definitely be a gas guzzler. 4.10's probably wont be an option till I make her a weekend warrior..oh well, it's all good I've just about had it with the AOD