Denying Warranty for Wrong Grade Gas

[sunedog]

My big sis has an Audi TT and the owners manual says you have to use premium fuel. She usually does, but occasionally uses mid-grade. Someone told her a dealer can somehow analyze the fuel if she brings it in and if they say it's not premium, they will deny warranty coverage.

Sounds fishy to me. Can 1) techs determine what grade of fuel is in the tank and 2) can they legally deny warranty coverage for using the wrong grade of fuel?

[MTI]

Only if the cause of the Warranty claim is the grade of gasoline. The mere use of the fuel doesn't void or interfere with the warranty's coverage unless Audi of America can show that the improper fuel grade was the likely cause of the claim.

[sunedog]

So do you think they can tell what grade is in the tank?

[MTI]

Actually, octane is pretty easy to test and determine, but more likely the car's data system will likely report that the engine timing was retarded due to the anti-knock sensors detecting predetonation.

[JEBalles]

I don't see why not. Engines that require premium fuel have higher compression and using lower octane gasoline will cause the fuel to ignite prematurely=nailing/knocking, no? So if you bring a nailing engine to the dealer, I imagine they will void your warranty. If you bring it in for something else, then unless it's routine to check the fuel octane, there's no way for them to know. It's like using more than B5 in a diesel engine will void your warranty.

[Ara T.]

Tell her to stop being such a cheapskate. Work the numbers with her and she'll see that the difference in gasoline cost over a year won't amount to much more than an extra $100 or so bucks for premium (depending on how much she drives).

[OldPokey]

Originally Posted by Ara T.

Tell her to stop being such a cheapskate. Work the numbers with her and she'll see that the difference in gasoline cost over a year won't amount to much more than an extra $100 or so bucks for premium (depending on how much she drives).

X2 - it's not like she bought an econobox. Maybe she should trade it in on a Prius.

[thorsen]

Assuming 15,000 miles per year, at 25 mpg, is 600 gallons of gas per year.

Premium is typically $.20 more expensive then low-grade. 600 gallons at an extra $.20 is only $120. Spread over the year.

[Matt L]

Unless you can't get premium. I've been in that situation before, needing 93 octane, but the choice was 91 otane or call a tow truck. I could tell too and had to keep my foot out of it; no computer on that car.

[pawoSD]

Yeah really, she can afford an Audi TT but can't afford to put premium in it?

[Oracle12345]

yes there is tools out there to see what grade gas you are putting in and also they can take the warranty away since the warranty will not cover things that owner should know better. Come on she can afford a 30 grand car yet she cant put premium in it? Also she cant read the owners manual? Something is really wrong with the picture. A few ways to determine it is checking the engine timing, how it drives, the times of combustion and actually take a sample of the gas and have it tested. In short with the technology available today its kinda hard fool people

[pawoSD]

It probably says right by or inside the gas door (or maybe even right on the cap) that it requires premium. Thus its her fault.

[PaulC]

If the timing retards because the knock sensor senses a lesser octane of fuel, won't fuel economy be affected? I wouldn't be surprised if the fuel cost per mile remains the same if she runs the vehicle on the recommended grade of fuel.

[pawoSD]

Very likely yes. In my 300E the best MPG's I've ever seen were with some super 93 octane fuel I found in Chicago....I got 26.2 highway over a 400 mile trip....going 75mph! Normally I only get around 24.5....as the premium I usually use is 91-92

[Oracle12345]

Originally Posted by pawoSD

It probably says right by or inside the gas door (or maybe even right on the cap) that it requires premium. Thus its her fault.

probally right on the instrument cluster....