Is it true about Gas on this article?

[dragon1761]

Does it make a difference or not whether i put 87 or 91 since our car adjusts for the temp in which the gas burns? Gas prices are gettting ridiculously high and i need to find ways to save.

[Dackelone]

Garbage in... Garbage out!

I would ONLY use Premium gas in my car! What you decide to use in yours is your decision. Yes, to a certain extent the car will de-tune the engine's power. But over time you could build up deposits and carbon - with sub standard gas/octane/tier-brand name fuels.


Dackel

[FDM68]

Think knocking and pinging, which is actually unburned fuel turned to carbon and detonating in your cylinders. Gas is not cheap true, and destined to get worse with world events, but messing up your engine in the long run will cost more.

[texasmojo]

I have always used 89 octane. No problems.

[Yvette]

premium gas will burn slower, hence better mpg imo.

[BrokenVert]

If the engine isn't designed for 87 don't use 87.


It's like you eating at burger king instead of making an organic salad.

Sure the BK is cheaper, but it's awful for your body and over time will make you fat and slow. It's the same for a car

[Red135]

In a 135 I wouldn't use less than 91, but he has a 128. He won't have any problems using 87.

[Bimmer-Bob]

For both cars, the manual states that the "recommended" fuel is 91 octane, whereas the "minimum" is 89 octane for the 135i and 87 octane for the 128i.

I just use the highest available. I didn't buy a BMW to cheap out on gas.

[Tom K.]

The 128i will run on regular - but under certain conditions, the timing may be retarded, resulting in poorer performance and mileage. If so, the mileage should not suffer by much more than 5% or so over a tankful.

I look at the price difference between 93 (in my area) and 87. If it is less than about 7% (ca. 20 cents/gal), then 93 (or 91) is a no brainer. If the difference is 10% or more, I generally alternate tanks.

Tom

[Xyloft]

every time someone says "wow you have to put premium in that? that sucks!" I do a bit of math for them:

average fill up 11 gals. difference between 87 and 91 in my area? 22 cents / gallon. so roughly 2.50 cents a tank. even if you fill up twice a week, we're talking $5. that's less than an average value meal.

[supraking]

If you want to save money, get rid of the BMW and get a Honda or Toyota. Cheaping out on gas isn't going to cut it. Or, better yet, pick some other part of your lifestyle and make a change. Reduce energy consumption at home, buy food in larger quantities and freeze it, go out to dinner once less per month... lots of ways to save money, I don't see how 87 vs. 91 is going to really save you anything.

[fwmcb]

Originally Posted by Dackelone

Garbage in... Garbage out!

I would ONLY use Premium gas in my car! What you decide to use in yours is your decision. Yes, to a certain extent the car will de-tune the engine's power. But over time you could build up deposits and carbon - with sub standard gas/octane/tier-brand name fuels.


Dackel

+1

[JimD]

I used premium, 93 octane, for the first 5k miles or so. Since then I have used 89 octane unless I was running an autocross or something. I do not notice a difference in performance but I don't push it very hard in my daily commute.

Jim

[Hocky]

Originally Posted by e90sexion

premium gas will burn slower, hence better mpg imo.

False. Higher octane fuel actually has less stored energy, resulting is lower fuel mileage. The reality of it is, though, that the difference is so negligible that there is no difference.

If you don't drive the car hard, you're not going to hurt it by running lower grade fuel - especially in an NA car.

[BrokenVert]

Ummm more false to you

High octane gas, although having less energy also has less enthalpy.

High octane gas Has a slower and more progressive burn. It is a constant pushing rather than a quick hit. The constant push is more effective at generating physical motion (piston motion) and is more efficient. Ie you need less fuel.

Higher octane gas gives better burn and mileage. It's a cost to benefit thing tho. 110 octane is more efficient than 93 but that's $10 a gallon so it's not worth it

[tritonx]

The difference it makes per tank is a few dollars why risk it. You drive a "luxury" car. A few dollars more per tank shouldn't be a problem, threat your car with what it was conceived for.

[Satalite]

Originally Posted by TrackRat

I should know better than get involved in these pissing contests but there is so much false information posted online it's maddening...

High and low octane fuels essentially contain the same energy.



Higher octane fuel does not necessarily burn slower. Octane is a rating of the anti-knock qualities of a fuel NOT the power output or burn rate. High octane fuels can be designed to burn faster or slower depending on the application. Higher octane fuels do not necessarily produce increased mpg either. These are false perceptions. How the fuel is formulated and the specific application will determine any difference in mpg or power. In actual practice the faster burning fuel that does not detonate delivers the greatest power to the crankshaft.

Now, with that said, as has been noted you are generally taking $3-$5 difference between regular and premium when filling the tank. Using the proper fuel for your engine is preferred. Lower octane could cause spark knock, retarding the ignition timing and lowering mpg. There are many variables but unless the small cost savings really means a lot to you, you're better off to use the proper octane fuel specified for your engine.

+1

I have been running between (87 - 89 octane) for 2 years now and can tell you that there is no noticeable difference. As stated the difference is ever so slight to people who drive the car and not track it.

Lower octane as stated by TrackRat could cause a few problems over a long period of time with the engine, but most people don't keep their car over 5 years. I would believe BMWNA car's engines are designed so that running on 87 octane wouldn't produce any problems. If it did, you would see a lot of people taking their cars b/c of this issue no?