Hi all,
I've searched the archives, but I'd just like some real time confirmation of a question I have. Will using 89 octane do any harm to my motor? If it's just a hp loss, I'm cool with that. What I'm focusing on is the harm factor.
Thanks in advance.
what octane does the owner's manual suggest?
The e46s require 91 octane but you CAN use 89. Just at the cost of performance. Your timing will be retarded (literally) and you might get some knocking at high rpms. It wont necessarily damage the engine but you will have more carbon deposits due to the smaller amount of cleaner in the fuel. The main thing you have to think about is the price. Is it really that big a deal? The 3 series has a 17 gallon tank. Here in the bay area premium and plus is a 10 cents difference. Premium is 2.00 so when I fill up 17 gallons (dry) it costs 34 bucks. If i use plus, its 1.90x17 which is 32 dolars and 30 cents. Thats a difference of 1.70! The extra injector cleaner in there is worth it alone. And you have the comfort of reving the engine to 6500 rpm without worrying about detonation. And you wont be filling up 17 gallons at once so the difference will be even less. In a year, all you will be saving is 20 bucks. But again the choice is yours.
yup....when you do the numbers, it doesn't make that much sense.
Regards
