ghurty

Hi
If you rent a car an Audi A6, are you required to put premium fuel into it? If not, do you get a better MPG if you do?

Thanks

gj83

I have an audi TT and would never imagine putting anything less than the recommended fuel into it.

I think the car gets mad at you if you put less than 91 octane in it. I don't think it's MPG, i think it's functionality. The fuel door of my car clearly states 91 octane or above.

DWilliamson5002

Yes MPG will suffer as the fuel is not burning properly. The engine will be mad at you and may set off the engine light if you arent careful.

best

Most newer midle priced cars automatically adjust engine to the fuel you put into it.

JLewisinSyr

I've never put anything but 87 in any of the rental cars I have had...

STS, H2, G35, M35, FX35, Azera...

Bonzz

I drive an 05 A6 and like someone said above, I wouldn't dream of putting anything less than premium in it. The fuel door does say 91 or above only. All that said, I'm sure the car will run on lower octane fuel (though the engine may knock a little more and performance and effeciency would suffer). Besides, the A6 is a delight to drive...optimize the experience.

DWilliamson5002

Untrue. While newer cars a Multi Displacement and Variable valve timing they cannot adjust to the octane rating. The different octanes burn a different temperatures and engines are set on compression ratios which is also key in the octane rating.

Some vehicles recommend 91 or 93 while some require it...

Using the wrong octane fuel rather above or below the requirements will eventually cause a knock and ping in the valve train. Putting 93 in an 87 vehicle will burn the piston rings as well as the previous.


Never buy a previous rental that REQUIRES premium fuel as seen in an above post people put regular in the tank instead. Being stuck in a bind with only 87 gas will not be that bad one time but over the life it will kill the engine.

nwaaok

It really depends on the motor the vehicle has. If it was a dual branded motor that was also put into a Volkswagon, I wouldn't think twice about putting 87 octaine in it. For instance, I had a Cadillac SRX with the Northstar 4.6L V8 that would violently shake and nearly stall out on cold starts if it wasn't sipping 93 Octaine fuel. Once I had some premium in the tank, it would run like a charm. It really depends on the vehicle. I wouldn't be too worried about it in a rental...

ctkw

Wow, I do believe there are many just refuel with the cheapest, lowest grade gas on a premium car requiring high octane gas!

skAAtinsteph

My Saab asks for premium gas and that's what it gets. The SO once put in regular and it ran like crap. I couldn't wait to get through that tank of gas.

On the other hand rental cars no matter what they are get regular from me.

dvs7310

Sorry to stir up an old thread, but I ran across this post and had to reply. Don't let that dual branded engine thing fool you... all except the base Volkswagen engine also requires premium fuel. Most VW engines and other European engines (ie, Saab, Volvo, MB, Mini, etc) for that matter are very small displacement with high output (usually via a turbo or supercharger) and premium fuel isn't optional in the long term. Putting low grade in it once or twice won't hurt a thing but you'll mess things up if you do it for the life of the car.

Reindeerflame

Another view is that if the vehicle does not ping with 87, it's OK to use it, and that vehicles of this nature really only require premium fuel when used in a high-performance mode. Like accelerating at maximum effort on a steep hill.

My rule of thumb is to start using 87 when gas exceeds $3.00/gallon and to avoid maximum load on the engine.

Dr. Bill Wattenberg, "smartest man on radio", KGO San Francisco 810AM, Sa-Su 10pm to 1am, agrees with this view.

My MB has 130000 miles on it and I have never noticed a difference or any ill effects.

I do tend to buy the premium because of the psychological boost it provides the driver.