KOMETA

What is actually this option? How important is having it on a vette with automatic transmission?

Thanks!

boatboatboat

I have an auto with the 3:15. I struggle to get the tires to break loose, with 3:15's. I would think that the 2:73's would be even worse.

If you have a choice I would get the 3:15's if possible. From what I have read you only loose about 1-2 mpg.

Larry_Yerton

3:15's are nice but if you really want to wake the car up get some 3:42's and say goodbye to the run craps

LBear

3.15 are MANDATORY

They make the car FASTER and it is much more fun to drive. 3.42s would be better but they are NOT factory options with an A4.

Mike Mercury

here are some ways to determine what rear gear a C5 has:

http://mikemercury.home.att.net/ratio.htm

Sully C5

3.15's provide better acceleration. Here is GM's info:

Axle....0-60 MPH...1/4 Mile
2.73...4.90 Sec....13.65 Sec
3.15...4.75 Sec....13.50 Sec

USA-VET

Ok, I'm gonna show some stupidity now! When I got my 99 A-4 I did'nt know that it had the G-92 (3.15). I wanted 3.15 or 3.42's bad! Well then I drove a friends A-4 and thought he had some motor issues because it was weak. Then I had SpongeVette do a born on date and wala, I have 3.15's. So my point here is GET 315's or get the 2.73's with the understanding that you MUST replace them soon!



P.S. Now I want 3.73's BAD!

Vetteman Jack

If you want some decent acceleration performance from the automatic, you should get the 3.15 axle. However, a number of forum members have ultimately swapped it out for 3.42's or lower gears.

'06 Quicksilver Z06

I don't know what the allure with 3.15s is. "Performance" differential???? If you want performance, you'll have to go beyond 3.15s.

Having driven a 2.73 geared car, my own, before the 3.42s and an '04 3.15 geared car, there is not a dimes worth of difference between the 2.73s and the 3.15s. As evidenced by the 0.15 difference in quarter mile times described above.

You'll have to replace either one if you are looking for real performance.

Sebring_C5

C5 4 ME

I X L R 8

I went from a 2.73 gear to a 3.42.

it's like bolting 100hp to the car.
as mods go, this is the most defining seat of the pants performance mod
in its price range.
GM suggests the 3.15 performance ratio.
I suggest what GM doesn't deliver in a 3.42 gear as A4's go.

I X L R 8

Oh youre wrong about that my friend.
theres a very noticable difference between a 2.73 gear and a 3.42 gear.

wildman378

the performance ratio is a must. Having 3.15's (c5) or 3.07 (c4) is like the 6sp's have 3.73's. See manuals always haved to be geared lower (higher number) to make up for it being a 6sp with the pauses in shifting etcetc. So when manual guys upgrade gears they go to 3.73-4.10 and a4's 3.45-3.73.

in a c4 a 3.45 geard 6sp pretty much is like having the 2.59's in the auto.

the 3.07 auto c4 is like a 6sp having 3.73.

you can tell a good bit of difference the 99 I had before my 95 vert had 2.73 and my c4 with 3.07s gets a better track time so it makes a lot of difference.

'06 Quicksilver Z06

I think you misread what I said. What I said was that there is not much difference between a 2.73 geared C5 and a 3.15 geared one. I have driven them both. The 3.15s offered little over the 2.73s I felt.

And I agree with you, that there is a very noticable difference between a 2.73 geared C5 and a 3.42 geared one. Actually the difference is huge. I should know by now. My car has had 3.42s in it since this past spring, upgraded from 2.73s.

SphyNxXx

Hmm.....my 3.15'ed C5 has had traction control/active handling kick in quite a few times while punching it from a roll....much less a stop!

Jeffyvette

I can break my tires loose at will under 35 mph, let alone from a stop. Now I have some mods also. But I like the top end speed of the 3:15's I hit 164mph 3nights ago with the top down. The 30 mpg at 85 mph is really nice to for a long trip. You guys might beat me off the line but lets go play on the freeways sometime (oops sorry that's right no one from this forum would do that)

Mike Mercury

I agree with you there.

But also like you; I also have driven C5 A4s with 2.73, 3.15, and 3.42 and I could tell a difference between them almost instantly.

Give me any C5 A4 (without telling me the rear ratio), and I bet that after two dead-stop launches I could tell you the ratio (without going 75mph in 3rd gear... HE-HE ).

Many here aren't into modding... and simply want what's the best the factory has to offer; and I think that was the post originators question.

Obviously the 2.73 to 3.15 is much more noticeable (15 percent change) than the 3.15 to 3.42 route (8.6 percent).

George8211

Maybe you should consider a higher stall Torque Convertor to go with your 3.15 axle.

GrandSportRob

I have the 3.15 rear in my 99...You can feel the difference when you hit the gas pedal hard!!....