R8 GT Fuel Tank

[steveo]

Some of these cars have the smaller tank standard but could be optioned with the 23 gal (90 litre) tank.
Has any one done retrofit of the bigger tank and how easy would it be?

[slammedr8]

I thought all R8s had 90 liter tank?

[steveo]

Nope they put a crappy 75 litre tank in the GT.
Even the Spyder GT has a bigger tank standard (80 litre) than the GT Coupe!

[slammedr8]

So what size do most R8 V10 coupe and spyder have?

[steveo]

Normal V8 & V10 Coupe all 90 litre, Normal V8 and V10 Spyders 80 litre

Its putting me off buying a GT with a small tank having to fill up every 150 miles, reminds me of my E60 M5 PITA!

[slammedr8]

Thats interesting...I just went on to Audi.ca (canadian site)

and it shows that they are all 90...

What do you think desperado?

[desperado]

I know the R8 GT is available with two different sized fuel tanks, just like steveo said. The standard tank is 19.8 us gallons (75 liter), and the optional tank is 23.7 gallons (90 liter, same as the standard tank on the non-GT R8).
R8 GT US order guide

My R8 GT has the option tank.

Since it was installed as an option by Audi at the factory I don't know how difficult it would be to retrofit it. I think the parts should be available through the dealer's parts department. ETKA would show how many parts have different numbers and would have to be changed. Besides the tanks themselves, some parts which might also be required could be the straps / brackets which retain them, the fuel senders if the depth of the tank is different, and the filler neck and perhaps some of the other plumbing might also be different lengths. I would not be surprised if some coding of the dash would be needed so the fuel gauge would read accurately.

There are aluminum plates on the bottom of the car, located under each of the two fuel tanks. One is located on each side of the car, behind the cabin and in front of the engine. I've never seen the plates removed, but I believe this is how the tanks are accessed. [EDIT: See correction in a later post, below] The service manual should show the procedure - erwin.audiusa.com.

EDIT: Turns out not all regular R8s have the 90L tank. At one time the 75L tank was apparently the standard tank in the V8 in some markets: How big is your fuel tank?

[desperado]

I followed my own advice and looked at the AudiUSA.com website. I found that the R8 GT and its specifications has been removed from the site since I last visited it several weeks ago.

[steveo]

Sounds like its a major job then and best to buy with option tank.

[Rated///M]

I didn't know it was an option to have a smaller tank on the GT. Seems like a dumb option to me? If you want the car to be lighter, can't you just put less gas in? What does having a smaller tank actually do for the car? Save 5 lbs?