What octane gas do you use?

[YETTI]

Just wanted to what octane rating you all use and your opinion on it. I usually run 89 with the occasional tank of 93. And I drive a 2006 4.4i

[tomsawyer]

If I remember correctly, doesn't the owner's manual recommend using at least 91 Premium? Anyway, since day 1, I've always used premium.

[YETTI]

Yes it says 91 or higher just much more $$ then 89

[diyanich]

Minimum AKI 87 is stated inside the filler cover door.
I constantly fill Esso 89 which is midgrade in Maritimes

[X53Jay4.8is]

Originally Posted by YETTI

Yes it says 91 or higher just much more $$ then 89

You should take a look at the price of OEM cats for your X5 because a sure way to a premature killing of a cat is wrong octane fuel (lower grade than is recommended). As we say save a little at the pump pay alot in maintenance later.

[kvc]

Originally Posted by trader4

I've been using regular for ~100K miles, 2002 3.0, currently at 175K miles.
Also, there are some folks claiming that premium will result in better
MPG, pay for itself, etc. I tested that a couple times, running the same route
with regular and premium, saw no difference. If I wanted to do a
0 -60 test, then I'd be using premium to make sure I got the absolute
max performance.

I beg to differ. In my experience, I have far better fuel economy using a higher octane fuel, than 'regular'. Moreover, my engine seems to run smoother and is slightly more responsive.
As many others have said, the modest difference in cost to fill up your tank is akin to buying 'OEM' filters as opposed to 'generic' when servicing your car IMHO. I like to think I'm doing the best I can for my pride and joy, and she will perform accordingly, by providing reliability and pleasure.

[weiln12]

Originally Posted by kvc

I beg to differ. In my experience, I have far better fuel economy using a higher octane fuel, than 'regular'. Moreover, my engine seems to run smoother and is slightly more responsive.
As many others have said, the modest difference in cost to fill up your tank is akin to buying 'OEM' filters as opposed to 'generic' when servicing your car IMHO. I like to think I'm doing the best I can for my pride and joy, and she will perform accordingly, by providing reliability and pleasure.

This has been my experience as well. Heck, even in my FJ that "recommended" 91 but ran on 87....I ran it on 91 because the performance and gas mileage more than made up for it.

[kvc]

Originally Posted by trader4

I think your emotional attachment may explain a lot. BTW, I use
Fram, Mann, whatever name brand filters are available and change
the oil at 10K. 175K and all is well.

I wasn't implying you used generic parts when servicing your car. I was using this as an analogy. That said, it's entirely your choice what type of fuel you fill up with. You may even choose to use an ethanol blend, as it is less expensive and may provide you with satisfaction too. I was simply posting a reply and providing my opinion for the collective knowledge base.
As is clear to see, from Q's post, the recommendation from the manufacturer is to use a 'better' quality fuel.
Yes - I think it would be fair to say I have an 'emotional attachment' to all my vehicles, as I've worked hard to pay for them and unlike some other people out there, I treat them with the respect they deserve, as opposed to simply considering them as a mode of transport. If the latter were true, then I somehow doubt I would have bought a BMW (and other quality vehicles)... but since I have, I will continue to follow the recommended quality fuel, oil and filters in an effort to achieve a relatively trouble-free period of ownership and have peace of mind.

[StephenVA]

Only Sunoco or Shell Premium (Hi test) 93 Octane US

So far I had to fill up the X5 once in the last 30 days as it is sitting quietly under it new Weathertech cover after being washed, clayed, waxed and detailed. Love the new cover!

California Car Cover - California Car Cover Company - Car Cover Materials

[maharaj1]

Originally Posted by StephenVA

Only Sunoco or Shell Premium (Hi test) 93 Octane US

So far I had to fill up the X5 once in the last 30 days as it is sitting quietly under it new Weathertech cover after being washed, clayed, waxed and detailed. Love the new cover!

California Car Cover - California Car Cover Company - Car Cover Materials

This right here.

Shell or Sunoco 93 Octane in all of our BMWs. Don't hear many people cal it High Test anymore. Always try and keep it above 1/4 tank to avoid excessive wear on the fuel pump. In my opinion it is worth the couple extra bucks for fill-ups. many claim that these engines run better with 93 Octane as opposed to 87 and I have verified this.

BLUF: When running at operating temperature an N62B48 ran with slightly lower rough running values when running 93 Octane as opposed to 87 Octane. Deeper explanation is below.

When home between assignments I work at a shop in Georgia and have access to an AutoLogic Diagnostic Computer. This computer is an extremely powerful tool with the ability to program and code BMWs given you have the proper software and know how. One of the features of the AutoLogic computer is the ability to read rough running values of certain vehicles, I did this test on 2006 750iL N62B48 motor with approximately 113,00 miles on it. Unfortunately I no longer have the saved screenshots as this was done several months ago and they were deleted off the hard drive. Customer complained the car felt like it was running rough despite having not DTCs. Hooked the vehicle up and found no current or saved DTCs. First thing I asked after scanning the vehicle was what octane gas he was running in it. He only fueled at Shell but was running 87 Octane with the occasional tank of 91 every several fill ups.

I explained to the customer that I only ran 93 Octane in BMWs and that wee that all our customers do to keep their motors in the best possible condition.


This was one of the first vehicles I diagnosed with the AutoLogic system and eager to see what
Vehicle was ran with both 87 and 93 Octane fuel from the same Shell station, while the car was at operating temperature. Rough running values were approximately .10-.15 lower across all 8 cylinders when the test was done with 93 Octane fuel. Lower values are better for this test. Values around .70 or higher suggest poor combustion. The values in this car ranged from .45-.55 with the 87 Octane and .30-.45 with the 93 Octane meaning the car ran smoother with the 93 than with the 87. Keep in mind that this test was done in the real time and not in a lab or experimental facility where we could control every variable. The parameters that we had control of such as engine oil and water temperature, ambient air temperature, fuel, and testing environment were kept constant for both tests. These values are approximate since I don't have the screenshots anymore.

Sorry for the long post/rant but the more information the better.