[smthomas77]

What octane is acceptable for the X3? Any consensus specifically for the X3 or BMW in general nowadays? I believe BMW recommends at least 91, but I also assume some do not follow that. My last BMW was an E46 3 series and I ran 89 in it as a compromise and never had an issue.

I know someone is probably going to flame me for even asking and probably state I shouldn't be buying a BMW if am that concerned about the cost of fuel. I'll call BS in advance so I don't need to respond later. There is a difference between not being able to afford something and wasting money. Only a fool would voluntarily waste their money. I think it is a legitimate question for that reason.

Thanks.

[ramparts]

Originally Posted by smthomas77

What octane is acceptable for the X3? Any consensus specifically for the X3 or BMW in general nowadays? I believe BMW recommends at least 91, but I also assume some do not follow that. My last BMW was an E46 3 series and I ran 89 in it as a compromise and never had an issue.

I know someone is probably going to flame me for even asking and probably state I shouldn't be buying a BMW if am that concerned about the cost of fuel. I'll call BS in advance so I don't need to respond later. There is a difference between not being able to afford something and wasting money. Only a fool would voluntarily waste their money. I think it is a legitimate question for that reason.

Thanks.

It'll run, but it's a long known fact that turbo engines run better on higher octane fuel.

Test it for Your self, run a full tank of each back to back, letting it get as empty as possible.

At least in the uk, there's a noticeable difference in standard and premium fuel.

Even my wife noticed it when she put supermarket fuel on her Mazda , and she's not a car person

[BMWZ4]

What does your manual suggest...

[rob175]

Currently I'm paying $2.35/ga for 93 octane premium at my local Sam's Club & Costco. I'm not sure those stores are in Canada or not. Around here (Chicago area suburbs) 93 octane at most gas stations is over $3.00/ga....so $2.35/ga is reasonable.....and I'm getting over 29 mpg around the area.

[Bob in IL]

Originally Posted by BMWZ4

What does your manual suggest...

This is a good place to start...

[freshxdough]

It is recommend to use 91-93 octane however 89 is minimum. Octane has to do with the fuel itself burning in the combustion chamber. Using 89 could induce knocking or predestination which will result in pulling timing, and reduces power.

In the CA AZ NV we already somewhat run into this issue when using 91. It has been known that these few states have high octane gasoline with higher detergents and can result in more issues pulling timing compared to 91 or 93 in other states. You see it a lot when it comes to tunes in the lower west coast states. And it's evident in the logs as well.

So in terms of just operating the car, you can run 89, but you're not doing much of a favor to yourself or your vehicle if you're always wanting the most out of it. I drive my car pretty hard and often, and I don't want any timing and power getting pulled over sub par fuel and saving a few cents.

[Alias1431]

Originally Posted by smthomas77

There is a difference between not being able to afford something and wasting money. Only a fool would voluntarily waste their money. I think it is a legitimate question for that reason.

Thanks.

Using a lower octane fuel with result in pre-combustion, or knocking. The engine's knock sensors will detect this and "down-tune" the engine, reducing power. The reason people question/ridicule this logic is, why did you spend 10-15k more for the M40i (I am assuming it's the M40i), but then use a lower grade fuel to save less than a thousand dollars over the lifetime of the vehicle- a vehicle that now makes less power... If you're so keen on saving money, why didn't you just get the 30i to begin with?

That being said, feel free to use 89. It's you're vehicle that you paid for, and no one can tell you how you should use it. The knock sensors "should" prevent any long-term damage. I don't think it will be an issue.

[335idrive]

Originally Posted by rob175

Currently I'm paying $2.35/ga for 93 octane premium at my local Sam's Club & Costco. I'm not sure those stores are in Canada or not. Around here (Chicago area suburbs) 93 octane at most gas stations is over $3.00/ga....so $2.35/ga is reasonable.....and I'm getting over 29 mpg around the area.

$3.00 for 93 How did 2020 become the good old days?

[r0gue]

Haha! You said it. Paid $5.50 for 93 in my Merc the other day. Not to sound crass, because I certainly feel it. But I would never compromise on fuel in a fine car.

[Chief Orman]

Originally Posted by rob175

Currently I'm paying $2.35/ga for 93 octane premium at my local Sam's Club & Costco. I'm not sure those stores are in Canada or not. Around here (Chicago area suburbs) 93 octane at most gas stations is over $3.00/ga....so $2.35/ga is reasonable.....and I'm getting over 29 mpg around the area.

6.69 a gallon for premium in SF Bay Area

4.35 for E85

This is not a debatable point a high performance car with an 11:1 compression ratio needs high octane fuel…you will notice a difference unless you drive your car like a 90 year old

[HTX3]

Simplified. It is about detonation. The higher the octane number the less likely the fuel is to start to detonate prematurely. If you run lower octane it may start to detonate early which will cause piston slap and premature wear. Some cars actually have sensors that listen for engine knock and can adjust things. Always read what the manual says and follow it. The engine has been optimized for that octane rating. There is XX octane recommended, which means you can run lower octane…and there is XX octane required. There are also different ways to measure octane, which tend to vary between the US and Europe. There isn't any more or less potential energy in different octanes it is where the detonation point is. Again, this is simplified and there is more to it.

[mailman_fin]

Hoh, you US guys complaing about the high prices.

Nowdays 98E (93 in US) here in Finland is about 2,3e/l

[misterdom]

Originally Posted by mailman_fin

Hoh, you US guys complaing about the high prices.

Nowdays 98E (93 in US) here in Finland is about 2,3e/l

If my math is correct that translates to roughly 10-12 USD per gallon??? They want y'all off those evil fossil fuels quick fast and in a hurry. Damn that's insane.

[mailman_fin]

Originally Posted by misterdom

If my math is correct that translates to roughly 10-12 USD per gallon??? They want y'all off those evil fossil fuels quick fast and in a hurry. Damn that's insane.

Maybe a bit under $9.5 per US gallon. But still, quite much.

I can only see friends in the gas pump

[Lenny_RDM]

Originally Posted by mailman_fin

Hoh, you US guys complaing about the high prices.

Nowdays 98E (93 in US) here in Finland is about 2,3e/l

On Saturday i pay 100$ that's insane, but the difference between Us and Eu is distance how many miles u drive a week….

Btw. Today I buy diesel to semi 1200$ that's for two days lol

[Chief Orman]

Originally Posted by mailman_fin

Hoh, you US guys complaing about the high prices.

Nowdays 98E (93 in US) here in Finland is about 2,3e/l

Yes but you are surrounded by smoking hot Finnish women

[mailman_fin]

Originally Posted by Chief Orman

Yes but you are surrounded by smoking hot Finnish women

Thats true!