Guys I was wondering if I maybe have 3.73's in my car. I was noticing some things today like 6th gear at 90 mph is about 2000 rpm. On a stock car from what I understand 90mph is about 1700 or so rpm in 6th. 1st gear ends at right about 40mph with 2nd ending at about 69 or 70 and 3rd runs to redline at about 90ish or so mph...is this the 3.42 gear set or 3.73's? According to the reading I've done it's 3.73's.

 

I have 3.73's and when Im at 70 the rpm gauge is at 1800-2000.

 

Thats in 6th gear too.

 

If anything wouldn't you have 3.23's or lower with that RPMs at that speed?? At 2000 RPM's in 6th I'm doing about 82 and I have 3.42's. If you go with a numerically higher gear your RPM's are going to get higher with less speed. Take my car for example, if I put 4.10's in it I'd probably be doing around 65 maybe at 2000 RPM's. Not really sure the exact speed. I'm sure other people will chime in with there experiences.

Myles

 

Try this, lift the rear of the car, turn the rear whell one full turn and count the number of times your D/S goes around.

 

Yeah I know how the gears and stuff work. I pulled out some old magazines earlier and they were turning 1400rpm at 70mph with their 6 speed thats why I was asking....Lt1Pony as for me turning less than a couple of the other guys on here and yourself I do have a 17 inch wheels. I was just curious cause I'm at about 90 or so mph when I'm turning 2000, and I'm turning about 1700 at 70mph vs magazines 1400.

 

Dont forget that your tach could be off too from factory or previous owner tinkering around if you're not the original owner. Gauges aren't perfect. Mine was about 100-150 RPMs too high in its reading before I put in my new gauges. People say M6s idle at 850-900 RPM and mine used to read 1000 so thats where I get my guess. Just my .02.

 

I did some gear calculations on my car and it doesn't seem to end up as 3.23's even though its bone stock, maybe a 3.42 was swapped in.

In my A4, 3rd gear @ 4500rpm is 85mph.