tallers

I was curious as to the Octane most people put in their B8 S4. I know the car calls for Premium (91+ octane) versus Regular (87 octane).

I have an 04 BMW 545i. I've run regular gas always with zero issues. I had an 02 BMW M3 which I ran premium in if I was doing around town, but ran regular for highway. The M3 would ping in city driving on regular, but was not a problem on highway.

My boys have VW's '02 & '05 Jetta & GTI. Both cars call for 91 octane but have been run on regular with no issues.

I've read many articles that speak to power loss and such but also say the timing adapts to the octane so they don't ping like days ago. I'm curious what people fill their S4 tanks with.

NWS4Guy

I put in 92, the highest availible here, you definitely lose power going lower, and while the engine does adapt for the lower grade so as to keep premature ignition from retarding the timing, it's at that power loss.

Calculate the cost savings you would get across the number of tanks, at ~15 gallons for a year, based on the price difference in grades, and it comes to a pretty negligable amount. The extra performance you get from the higher grade fuel will translate into better fuel economy, and help ofset some of the additional cost.

McGriddle

93 Octane only.

rktskicar

lucky ba$tard. we have the 92 eco friendly PNW craptrane.

NWS4Guy

With up to 10% ethanol

zillmc

For many years driving 540 -> 550 and other cars like Audi and Volvo that strongly recommend premium gas, I have found that using regular is a very steep and noticable decline in performace, as well as has a negative impact on the engine over the life of the car. Personally, it's one of my biggest pet peaves, I can't stand the fact that my mom has been dumping regular in her A4 avant since 2003, the thing totally has no ***** anymore. Even if I got free regular gas I wouldn't put it in my S4 or any other performance car for that matter. It's totally ludicrous to me.

boulderbobo

^^^Wish^^^

rktskicar

It's not just the Ethanol, it's the other crap they put in it.

canyoncarver

The average owner uses about 500 gallons of gas a year. Price diff on premium is about .25, so about $125 a year.

Seems somewhat foolish to worry about saving $125 per year buying cheaper fuel, for a car that retails for $50,000+.

patinsd

Very good point .
Thanks for the clarification .