sup all, I was wondering. I am going to do a M6 to an A4 swap. And I was wondering, what rpm are you guys running in OD at 80mph, stock rear gear? anybody with 3:73s?

wondering how bad my gas miliage is going to suck with the change.

 

Sorry Wouldn't know. 65 is the speed limit here in cali...

 

80 mph = 2400 RPM
65 mph = 1850 RPM

The stock 3.23 aren't that bad. I managed 28 mpg on a trip to Santa Barbara from L.A. and 25 mpg on the way back with the T-Tops off doing about 75.

 

my car has 2.73 and @ 80 the tach is at 2000 rpms.. I average around 28 mpg on the freeway as well...

Charlie

 

Wow, you're probably the first person on this board who has admitted they're doing an M6 --> A4 swap!! Most guys seem to want the opposite!

As far as revs go with 3.73's and the A4:

60 mph = ~2200 rpm
70 mph = ~2500 rpm
80 mph = ~2900 rpm

Those numbers are close, but could be off +/- 100 rpm.

I just installed the 3.73's in my car on Saturday, and so far I love them! I can't tell you much about my gas mileage though..............until now I had 2.73's, but I only ever seemed to get mileage equal to that of my age:

~21 mpg!!! (21 y/o!)...................I think I abuse the gas pedal too much though?!

 

I have 3.73's and an A4, and I turn 3000 RPM at 80 MPH.

Here is a handy sight:

http://www.f-body.org/gears/

SteveC

 

Damn that does not sound right w/ because @ 80 your rpms should be around 2800 rpms... But that is assuming you the 245/50/ZR16 tires as well.. If you are actually turning 3000 rpms, then it is true that the tachs are off...

Charlie

 

dmnall:

You are CORRECT, my bad, I am turning 2700 RPM at 80 MPH, I am turning 3000 RPM at 88 MPH.

SORRY FOR THE MISINFORMATION.

SteveC

 

I can tell you about my gas mileage after 3.73's it went all to hell.

Luckily I only drive it a couple times a week if that much.

 

I turn 2800 at 80 with 3.73s. My gas milage only went down a few mpgs from the prior 2.73s

 

No problem.. At first, when you were saying 3000 rpms @ 80 mph, I was thinking it must be in Drive on O/D... but @ 88 sounds about right in O/D... Be glad that these cars did not come with 15" wheels... my 68 C10 Project screams @ 3500 rpms at 80 mph... With TH400 (in Drive no O/D though) w/ 3.73 gears and 15" wheels...

Charlie

 

OD - 80mph @ 2400 rpm
D - 80mph @ 3500 rpms

 

I dunno where you guys are all coming up with these high rpms...I'm at like 2300 at 80 in OD like Gossco95.

I have the stock 3.23's, Loudmouth, Whisper Lid, Granatelli MAF, K&N Filter,
!EGR, polished TB, and Fernco Bellows.

 

I'm wanting to do the same A4 to A6 swap...Where did you get the parts? What kind of budget are opperating under?

I have 2.73's and at 80 my rpm = 2100 I believe.

Ideally I want a standard transmission, Hurst shifter, 3.42 gears.

Any opinions?

Jay-mak

 

i've got 3.73's and a yank 4200 converter

at 70mph im at 2050 rpm in OD
at 80mph i forget

Jerry