RPO codes/Window sticker
Thread Starter
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Joined: Jun 2019
Posts: 9
Likes: 2
From: Nashville, TN
RPO codes/Window sticker
I ordered the Build Sheet/ Window sticker set for my 1999 Convertible. I've been having a great time comparing the two and looking up what each code means. That is until I ran across a discrepancy. My build sheet says the car was built with the 3.15 rear axle ratio. The window sticker says it has the Performance axle ratio and was listed as costing $100. I'm guessing to resolve the question is going to require putting the rear end up high enough to read some code on the differential. I do have some interest in knowing which axle ratio I have and further, what the performance ratio really is. Generally I'm curious if this type of mismatch in the paperwork happens a lot during assembly of the car. Thanks in advance for any information anyone can share.
Thread Starter
Navigator
Joined: Jun 2019
Posts: 9
Likes: 2
From: Nashville, TN
I figured it was going to take a differential check. I just got the Build sheet set a couple of hours ago and I'm actually sort of dressed up at the moment as I'm taking my wife out for our 51st wedding anniversary. I'm not going to be getting around to inspecting the differential for a couple of days. Thanks for the reply.
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First - Congratulations on your 51st!!! 
(We are 3 months behind you).
Next - If I am understanding correctly you are questioning the difference between 3.15 diff on build sheet and the performance axle on the window sticker. Assuming you have the A4 trans, these are the same. The base C5 with A4 came with a 2.73 diff. The performance upgrade is the 3.15 ratio differential. IIRC you should show both G90 and G92 option codes on your window sticker and on the options list on the inside of your glove box.
(We are 3 months behind you).Next - If I am understanding correctly you are questioning the difference between 3.15 diff on build sheet and the performance axle on the window sticker. Assuming you have the A4 trans, these are the same. The base C5 with A4 came with a 2.73 diff. The performance upgrade is the 3.15 ratio differential. IIRC you should show both G90 and G92 option codes on your window sticker and on the options list on the inside of your glove box.
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Next - If I am understanding correctly you are questioning the difference between 3.15 diff on build sheet and the performance axle on the window sticker. Assuming you have the A4 trans, these are the same. The base C5 with A4 came with a 2.73 diff. The performance upgrade is the 3.15 ratio differential. IIRC you should show both G90 and G92 option codes on your window sticker and on the options list on the inside of your glove box.
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