yeah i mean this is cycling back around to what i started this post with saying, "i don't care to here that 93 is what bmw recommends" because bmw recommends a lot of things i'd like to shove up their ass. that aside, if you just say "not worth it" it doesn't sound like you know a lot about engine knock and what it actually is. if you are expressing worth in the dollar value of the change, you don't know my spending budget or driving habits. if i fill up 8 times a week and make 25k a year, i'd say the reinvestment is worthwhile.

all that aside, i just wanted to know if anyone has had problems with the 87, that's all. my bmw gives me enough problems on 200 miles a week, i really doubt the gas is going to make a difference.

 

No. No problems using it other than a decrease in mileage and pep. (and for all the Monica Lewinsky fanboys - I used 85 and 87 for 2000 miles two years ago and I have had NO long term problems - I use premium cause I like the pep!)

 

first off i drive a 550i, but i agree turboed cars are more prone to pre-ignition/detonation, but only when under boost.

you have some valid points, but its not just air density that matters. you also have to think that a engine runs with vaccum in the intake system, and the pressure change all depends on the throttle position.
with denser air, you will get more power and require less throttle, which is less of a load on the engine.

in the end, if i know i'll be doing a lot of highway driving, then i may choose to use lower octane.

 

If you're not concerned about what BMW suggests, then why even ask, just do what you want, and if you make 24K a year or fill up 8 times a week, then you need a different car. I cannot understand people who buy an expensive luxury car, and then contemplate running cheap gas, tires, and want to cut corners everywhere.

 

^this

 

I always fill up with 87 octane!! in loaner cars...otherwise it's premium only!

 

well some cars don't have good knock sensors. my ls1 would not run right on 87 EVER, however my mom's 350z runs just fine on 87. so each car is different, hence why i ask. never mind it being a bmw. my comment about bmw just reinforced how much i am starting to despise bmw the company for various reasons.

oh, and not that its any of your business what i personally make or why someone would own a bmw with a 25k salary (maybe their parents bought it for them?), but that was a hypothetical scenario nonetheless.

 

I have tested this before and what I found is I did not save any money. My MPG dropped when I wen with a lower octane. Just for a blind test, the wife accidentally put in 87 (which I did not know) and I figured it out when I got really bad MPG.

 

+1 IMO I believe he has a real problem owning a BMW and would be happy driving something like a Kia.
cheers
vern

 

Here's the bottom line, in an emergency, you don't have the correct antifreeze? water will get you where you need to go, you're low on oil? any regular gas station oil will do, you have a flat? the donut spare will get you back on the road, need gas but pockets low? reg will work, both your headlights blew at the same time on a dark road? stick a freaking flashlight out the window and get out of there!

These are all things I would do just to get home and then correct the problem, no harm will be done in that span of time, but running just any old oil, or water instead of the correct antifreze for long periods can have negative affects over time and I wouldn't do it. So running a tank of reg gas here and there, you may not even feel the difference, but there is a difference wheather you choose to accept it or not. When you're only talking about $3 per fill up on a car that retailed for over 50K, is there really a need for debate? Just seems silly.