When looking for parts, I'm usually asked to pick from a 2.8L VIN (A), or 2.8l VIN (C).. I always choose (A) since I see no (C) in my VIN, however, I'm wondering what the difference is.. becuase I never actually see one in the parts presented.. ??

 

you need to get parts for VIN A - it comes from the "4AX" (which grouping suppose to mean the "model").
Also, I bet you have the AFC engine too.

 

I do have the AFC, however, the VIN C is also for the AFC.. thus the confusion

 

http://s2central.net/vin_entry_sonic.html

 

If I'm not wrong, I think the difference is from FI vs SFI (MFI) .

 

Yep.. '4A' is C4 Platform, '4C' is C3 Platform

However, the problem is this.. I'm asked what engine is in my 1996 A6 Quattro (C4) (so it knows the platform)...

The options are:

2.8L FI VIN(A) (AFC)
2.8l FI VIN(C) (AFC)

Both are the same engine.. so the A or C cant really be the letter after the 4, can it?

The only thing I can think of is whether you have the updated accessory belt pully system or not?

 

heres and example from Rock Auto

2.8L 2771cc V6 FI (A) [AFC]

2.8L 2771cc V6 FI (C) [AFC]

2.8L 2771cc V6 MFI [AAH]

2.8L 2771cc V6 MFI [ACK]


There's 2 AFC choices....

 

When they ask (either on the phone or via listing on the web), I'm pretty sure is about the very letter after 4.

Some of these vendor refer to it as "engine code", some others as the "VIN".
When I first inquired about certain parts from some of these places via phone, I got really confused too.

Get the our VIN checked in that decoder and you find exactly what every number/letter means.