I have been searching and searching for this information for 2016 C7 with 8 speed paddle. How do I find out if it has a 2.41:1 axle, or a 2.73:1 axle?
I was reading the manual about shifting speeds when I ran across this. I have looked at all the documentation on the car and on the Internet and can't find out how to determine this. Any help would be appreciated.

 

A8 base C7 has the 2.41(as does the Z06) and the Z51 has the 2.73. M7's have 3.42.

 

Thanks.

 

Do you know what this ratios mean in real world driving. I would think the 3.42 would be quicker off the line.

 

You have to look at overall ratios:


Gear Ratios:
...........................A8....Z51A8.. ...MN7...Z51MN7
.........................------..------..------..------
First gear............... 4.56 .. 4.56 .. 2.66 .. 2.97
Second gear.............. 2.97 .. 2.97 .. 1.78 .. 2.07
Third gear............... 2.08 .. 2.08 .. 1.30 .. 1.43
Fourth gear.............. 1.69 .. 1.69 .. 1.00 .. 1.00
Fifth gear............... 1.27 .. 1.27 .. 0.74 .. 0.71
Sixth gear............... 1.00 .. 1.00 .. 0.50 .. 0.57
Seventh gear............. 0.85 .. 0.85 .. 0.42 .. 0.48
Eighth gear.............. 0.65 .. 0.65 .. .... .. ....
Reverse.................. 3.82 .. 3.82 .. 2.90 .. 2.90
Axle ratio............... 2.41 .. 2.73 .. 3.42 .. 3.42

Overall ratios:
...........................A8....Z51A8.. ...MN7...Z51MN7
.........................------..------..------..------
First gear...............10.99 ..12.45 .. 9.10 ..10.16
Second gear.............. 7.16 .. 8.11 .. 6.09 .. 7.08
Third gear............... 5.01 .. 5.68 .. 4.45 .. 4.89
Fourth gear.............. 4.07 .. 4.61 .. 3.42 .. 3.42
Fifth gear............... 3.06 .. 3.47 .. 2.53 .. 2.43
Sixth gear............... 2.41 .. 2.73 .. 1.71 .. 1.95
Seventh gear............. 2.05 .. 2.32 .. 1.44 .. 1.64
Eighth gear.............. 1.57 .. 1.77 .. .... .. ....

 

Thanks for posting. In addition you get torque multiplication from the torque converter off the line (as well as some inefficiency and less fun for some of us!)

 

Wrong ! Proven so many times at the strip through the traps. The A8 wins hands down.

 

Because of the super low 4.56:1 first gear in the A8, the 2.41 or the 2.73 is all that is needed for that quicker jump off the line.

The 3.42 rear gear on the manuals is because of the transmission limitations with their torque capacity(strength of the tailshaft), so the manual transmissions require a higher first gear ratio, and then depend on the lower rear gear ratio, to achieve overall gearing.

If you multiplied the engine's torque 4.56 times( A8 1st gear) and then 3.42 times(rear gear), you would most likely trash the axles and the differential and would most surely fry the stock tires.

It would require a 4.20 rear gear on the C7 Z51 M7 to have the same "off the line" gearing that the Z51 A8 has.

That 12.45 overall gearing in first gear(Z51) is really about as low as you want to go on the street.

 

Thanks for that info.