Actually, I think the car is saving itself from you (in running less than 91 octane)....

 

The one I quoted? Then you should tell the author. He may be interested in emperical data.

 

Amen to that. If it isn't in writing, it didn't happen. Good luck trying to recover for any engine damage that is due to running a lower octane gasoline where the SA verbally recommended you to use 87 octane gas....

 

Dynos have a margin of error... not to mention all the other variables that affect readings. Also all gas is not created equal... too many variables to base results on.
Octane is resistance to detonation... it doesn't mean its less powerful. It will cause damage from detonation if the burn is not controlled.

 

I use 93 octane only. Right around $2 more per tank over 87 octane.

 

actually, higher octane gas does have less energy per unit volume.
direct from my grad school officemate who helped develop
the additive package for texaco system 3 gas.

(we used to trade tips on how to improve his knock measurements on
his test rigs. these test rigs are the basis for the RON number at the pump)

 

I was referring to him using regular stating it is not less powerful than premium...

 

just to stir the pot a little bit more, remember this:

using higher octane than an\engine requires usually damages the engine by leaving carbon deposits on the head. Use the minimum ocatane your car requires, whatever that is, for long life.

gregc

 

the additive package for a particular gas determines resistance to carbon deposits. this is the first time i've ever heard that higher octane leads to increased carbon deposition.

 

Are you sayiing that there is no record of what ignition timing map is being used, or whether there was a value thrown by the knock sensor, or some other bit of information that a regional technical rep from BMW/MINI could use to make the case that the car was being driven with a lower octane rated fuel? Corvettes track EVERYTHING. With a Tech2 scanner, you can read the history of each bank's knock sensors, what ignition timing map was being used, and, and, and....

 

Check out www.toptiergas.com I would note that BMW is one of the manufacturers that have recognized the issue of detergent quality (in addition to the issue of octane requirement). While there is an on-going debate about the consequences of running gasoline with a lower octane rating, one bullet that can not be dodged is deposits to the intake valves. After ~10,000 miles running gasoline with low or no detergents, you will need to have the car's engine de-carbonized.

 

Except if you live in California (there may be other states that are similarly blessed, but I have personal experience with California). The highest "standard" premium fuel octane is sold at 91. There are a limited number of stations that sell 100 octane unleaded racing fuel, but those are few and far between.

 

What, exactly, is suppose to damage your MINI's engine if you use regular instead of premium? If, and even this isn't for sure, there is even the slightest knocking with regular, the ECU will slightly reduce timing which will stop the knocking.

I can't think of any other possible problem and if engine damage was going to occur just because you have regular in the tank then the millions of cars that use regular by design would be damaged from it. Since I have had many vehicles that I use nothing but regular in and drove them for over 200,000 miles without engine damage I find this hard to believe. Only severe engine knocking over a long period is likely to cause engine damage....this isn't going to happen even if you use 87 octane, let alone 89 octane gas.

Use 91 octane but relax, if you or someone else puts regular in your MINI it won't hurt a thing.

All gas contains detergents, how much would depend more on the brand of gas than whether it's regular or premium.

Rest easy.

 

I once heard that there is no difference between gas brands - that they all get gas from the same source. Maybe things changed, maybe the original information was wrong. I know that gas stations are strongly advertising their additives, but I'm doubtful about there being significant differences between brands. I've been using Sam's Club gas, because it's cheaper. I have to mix 93 and 89 to, hopefully, get an average of 91. I don't really know that the two mix - maybe I get half a tank of 93 and half a tank of 89?

 

I think you're right to be skeptical of any big differences in brands. Even the additves are simular, it's the advertising that differs. I like the Shell V-power ad with the fish. I'd use Sam's if we had one here. I use Shell because I have a Shell Mastercard that get's me 5% off. That's 15 cents/gal. right now.

 

While you are right that gasoline is basically the same (it generally moves from refinery to distribution location by pipeline, and there is NO way to segregate one batch of gas from another in the pipeline), the additive package is put in when the load of gasoline is sent out to the stations. There ARE differences in the additive packages. Check out www.toptiergas.com for specifics. I personally would not buy gas from a retailer that was not on the TopTier list, even if I was saving 5% each time I purchased. If you run gas with a marginal detergent mix, you will be looking at a de-carbonization of your engine in ~10,000 miles. Depending on the cost of a de-carbonization in your area, the 5% savings on gas will be eaten up by the de-carbonization effort (direct cost + inconvenience).

 

91 aka or better it is writtin on your cars gas cover

 

mini does not provide that type of info to the techs

 

Ok so I am looking at this list here.

TOP TIER Gasoline Retailers:

QuikTrip
Chevron
Conoco
Phillips
76
Shell
Entec Stations
MFA Oil Company
Kwik Trip/Kwik Star
The Somerset Refinery, Inc.


I can't use Shell or Chevron for well lets just say personal reasons but isn't shell and BP the same company now. I was pretty sure they had merged to form like Dutch Shell British Petroleum company or something. I know Exon and Mobil merged and I am not surprised that they are not on the list they have always though much to highly of their oil and gas. I always knew it was not as they said. Are Conoco and Sunoco related or not I have lost track of who has merged with who?

 

i just got back from alaska and from this thread, driving
an MCS up there is probably a total No-No.

the three grades of gas were 87, 88.5 and 90 by the (R+M)/2 method

didn't see a single mini in the 10 days wandering around the south-central
region (did see plenty of BMW's)

 

ConocoPhillips controls Conoco, Phillips, and 76 stations. Also, they own JET, but that appears to be a Eurpoean brand

 

Neither do Corvettes. Do you know how much memory and the power the ecu would need to store all this info? It's all baloney. There's no way to tell which octane table is used because both tables WILL be used during one tank of gas. The ecu is designed to use the higher octane table first, if it detects knock, then it will use the lower octane table.

 

Last I heard, 76 (otherwise known as Unocal) was on track to be acquired by ChevronTexaco. Until the acquisition is final, 76 stations are fueled by Unocal, which is not owned by ConocoPhillips.

 

Well, there is a data-logging capability to store from the most recent ignition cycle back until the log capacity is filled. Then, the oldest dataset is overwritten by the newest ignition cycles' dataset, and so on. Data logging ability varies depending on the model (C6 has greater data logging capacity (more data points and more data) than the C5); it also varies by model within the GM line. The ecu is not doing the storing. Rather, the ecu writes its memory contents (by ignition cycle) to a storage device. The storage device contents are then queried by the Tech2 scanner.