Thanks! I am convinced.

-G.B.

 

I always try to use 91 but sometimes I use the one just below it when I'm low on funds. I took my 2007 mini cooper s in to the mini dealers just a few days ago because the engine was "knocking" (?) and it was because I used the not so premium fuel. The service guy who has been helping me since I first got my car told me that even though many gas stations say its 91, only Shell, Chevron, and 76 (at least in the Sacramento area) are truly top tier 91 fuel. They recommend 91 because it has a lower content of ethanol which can mess up your engine, they have a little booklet at the dealers. You can also buy some sort of oil detergent to remove this stuff from the engine. Anyways, I've learned my lesson, always use premium.

 

You car will only require premium fuel if it pings on regular. If you put in regular gas and it doesn't ping, then you are fine. The gas itself is the same, the gas company simply adds octane to their premium grade. They may also add some cleaning agent but you can do that by purchasing some STP gas treatment and add it to a tank of gas after every few fill-ups.

 

As mentioned BEFORE the car detects predetonation and retards the timing to prevent it, this cuts down on performance and can cause SERIOUS engine troubles in the long run...but hey if you won't listen to a service manager or me go ahead and ruin your car

 

That's funny, because my service manager said "no added benefits." What's really funny is that we're all listening to service managers who quite frankly are usually retarded. In my 420hp V8 RS4, all I'd ever think about putting in my car would be 93+. With my wifes mini S, I still put in 93...but that's not what Mini of Tampa said.

 

One of the factors we are looking at while deciding whether to get an "S" or not is fuel cost.
Since it will be replacing our 2005 Prius, I'm a little sensitive to this.
Carol's car before the Prius was a 1998 BMW Z3.
89 octane was the recommended grade for that car.
As a test, I did run a tank of 87 octane through it, with a result of nearly 4 mpg less.
I always use Chevron (Texaco) or Shell for the cleaning additives.
Question: does the non-turbo Mini need 89 octane, or is it happy with 87?
Being an old-school type, it was always a rule of thumb that anything less than 10:1 on a normally aspirated engine did not require premium fuel, but I don't really know where the regular/ mid grade break point is.
I found a REALLY low mileage 2008 "S" that's tempting me, but I need to settle this issue.
Off topic: I drove the new Honda CRZ last week.
In "Sport" mode, the paddle shifters impose gear stops on the CVT tranny and it feels just like the auto version of the Mini!
Carol says it's not as cute, however, and you know how much weight THAT carries! :-)
OTOH, you can put the CRZ in "Economy" mode and get 58 mpg highway, according to Motor Trend.
Thoughts anyone?
Bob

 

Both state premium fuel only

 

Bad venge,
Are you quoting the Mini manual?
I was looking for some experience-based comment from someone who had actually tried mid grade or regular gas in a standard Mini.
It does appear that you and I are the only ones around!
Thus emboldened, I will give my layman's opinion that if you are operating a normally aspirated engine with less than a 10:1 compression ratio and not using an advanced timing setting, premium gas gains you NO benefit at all.
There. That should bring forth the expert commentary! :-)
One disclaimer: I do not know the compression ratio for the Mini engines.
Bob

 

I've tried mid grade as well as high test , my performance and mileage suffered on both the S and the regular mini's.
Also the deposits are what worries me

 

Look folks the S means it is forced induction! there is not a turbo or supercharged car on the planet that will run well on mid grade or regular octane gas. When I asked my dealer multiple people there insisted on premium. when they fill up the cars in their fleet they use 91+

I love people who sit and say "i did it and it worked" they always leave out "for now"

Problem with the internet is that you have to decide who is credible and who is not. why not google octane and try to understand what the number actually means. Its all about the threshold to combust the higher the number, the higher the threshold. High octane does NOT have more energy per volume it allows the explosion to occur in a smaller space with the same amount of air.

if the bomb goes off too early you waste the energy and damage the engine which is why Mr on board computer retards timing.


You do not buy a sports car if you do not want to buy 1K worth of tires every 15-20 thousand miles. Do not buy a high compression or FI engine set up if you do not want to pay 10 cents or so more per gallon. really for a 10 gallon fill you are talking about a dollar.