My mom just got a 2006 x3, not a bad car, and told me that the stealership said to fill er up with high octane fuel. I said she'd be fine with the middle level octane. What do you guys think? She has had the lead foot mod deleted.:eek: so she hardly ever drives overly fast or "acclerates with a passion". Thanks

There are essentially two considerations at work:
(1) You are in Calif., where the premium gas is only 91 octane. It is 93 in other parts of the country, so if others say you can use the mid-priced stuff, check what region they are in and what octane they are referring to.
(2) Modern BMW engines have a sophisticated engine monitoring system. They will run on any gas sold in the US. But the question is how efficiently will they run. After my X3 was broken in, I tried tanks of all three grades available here. I got the best mileage from the premium. I thought that I could notice less power with regular, but that certainly wasn't based on anything scientific.

So, you can try these yourself, or you can follow the price differentials. Or, you can pick a grade (probably NOT regular) and live with it. (P.S. I try to use Costco's premium--it is 91 and they only have two grades.)

Premium.

Premium.

+1

There are essentially two considerations at work:
(1) You are in Calif., where the premium gas is only 91 octane. It is 93 in other parts of the country, so if others say you can use the mid-priced stuff, check what region they are in and what octane they are referring to.
(2) Modern BMW engines have a sophisticated engine monitoring system. They will run on any gas sold in the US. But the question is how efficiently will they run. After my X3 was broken in, I tried tanks of all three grades available here. I got the best mileage from the premium. I thought that I could notice less power with regular, but that certainly wasn't based on anything scientific.

So, you can try these yourself, or you can follow the price differentials. Or, you can pick a grade (probably NOT regular) and live with it. (P.S. I try to use Costco's premium--it is 91 and they only have two grades.)
Thanks by01, u've got some great points. Ill keep them in consideration when I test the different octanes. Hope u enjoy the X3, seems like a great car so far!

It is also 91 in the Chicago land area.

My mom just got a 2006 x3, not a bad car, and told me that the stealership said to fill er up with high octane fuel. I said she'd be fine with the middle level octane. What do you guys think? She has had the lead foot mod deleted.:eek: so she hardly ever drives overly fast or "acclerates with a passion". Thanks



you might as well tell her to put diesel in...

i would not go less than 91 octane