I have a 2004 530I and is currently running Premium unleaded and with the gas price in Texas up to 4.29 a gallon for Premium and promising to get higher before the month of April runs out will running Plus unleaded damage my car ?

 

If you work out the actual difference between the cost of a tank of premium and the cost of a tank of regular or mid-grade it's pretty negligible... Your car will run fine on regular, it will adjust timing accordingly, but it may not give its all under all conditions.

As an aside, and this observation is *not* aimed at you, but if the the less that two dollars per tankful needed to fill up with premium fuel creates issues for anyone they probably ought not to be driving a premium German car in the first place...

 

The car is designed for Premium and it should be fed Premium. Yes the car will compensate for the lower octane, but it might cause some more costly side effects in the future.

 

Thanks Guys I am going to stick with Premium unleaded for all that it worth the car is running fine and I do not need that to change in any way ist for saving a few bucks.

 

Im glad to hear swajames set you straight...

 

Here we go again with the gas debate. You will NOT hurt your car by putting regular gas in it, unless you're running high compression as in most turbocharged/supercharged vehicles. You may experience slightly fewer MPG, and slightly fewer HP, although you're not likely to notice the difference unless you're really into performance. You SHOULD NOT let anyone guilt you out of saving money, whether you can afford it or not. Need proof?

Pay close attention to the 5th paragraph of the article:
http://forum.roadfly.com/threads/126...ctane-gasoline

 

Seems to me, the bottom line supports SWAJAMES contention. It's just a few bucks you're saving... and even that's questionable. If you REALLY want to save money, look for a car which is designed primarily for the budget conscious.

And that is not BMW's market I'm sorry to say!

(Good article, BTW.)

 

Petrol/Gas prices in Germany - $7.66 a Gallon

A friend of a friend visiting from Germany. This is what they have to deal with!


http://www.flickr.com/photos/gamingfloor/5489877909/

 

The actual quote from that 5th paragraph supports exactly what pretty much everyone here has posted already - the car will run fine with regular fuel, but it will not perform its best under all circumstances.

"Thomas Plucinsky, BMW Product and Technology Communications Manager told us all BMW engines are designed to run on 91 octane. All performance testing, including EPA emissions and fuel mileage, is done with 91 octane. However, though BMW is all about performance, their motors will run on 89 or 87 octane without damage. The knock sensors pull the ignition timing back and eliminate detonation. There will be a loss of power and a decrease in fuel mileage, but the size of the horsepower loss and the increase in fuel consumption depends upon many factors, such as ambient temperature, exact formulation of the fuel and driving technique, so BMW does not offer any estimates for operation on lower grade fuels. One not so obvious concern, Mr. Plucinsky noted, is the type and quality of additives the gasoline companies include in the fuel. Premium gasolines may have better additive packages which are more effective keeping fuel systems (particularly injectors) clean and working efficiently, than those in regular grade fuels or off-brand products. Using lower octane or off-brand fuel could be degrading the fuel system over time, setting you up for a repair bill down the line."

Simply put, for the sake of a couple of bucks per tank, why suffer the performance hit (and BMW acknowledges that there is indeed a performance hit) and why take the risk?

I am back to my original contention. If a few bucks per tank is a big enough deal to you to go against the manufacturers recommendations, you really have no business whatsoever being in a premium car.

 

Search will provide tons of info if you should or not. Some say they have higher MPG on 87, other like myself saw a reduced MPG and the test (5 weeks) proved that there was no savings. I cannot add any more other than search and you will have plenty of reading