I know this will probably be construed as a stupid question but does the Mini require premium grade gas to function properly? Everyone always crows about the great milage that this car gets (30 + by most accounts) but this is one thing that scares me away from getting one.

I accidently pulled up to the prem. pump here in So Cal - 10 gallons and $30 later I had myself a full tank of 91 octane. My father worked for Ford for years and he always taught us that high octane gas was a waste since most cars are meant to operate on normal grade. I know very little about cars so this is an honest question. It seems plausible to me that the whole tiered system of gas grades is designed to take advantage of the car purist who is willing to go to any length to ensure that they protect their beloved car.

It seems like this requirement negates the $ advantage that one would derive from driving this auto. I am a big fan of a clean environment so I can understand the desire to get a high MPG # but I am an even bigger fan of a high $ # in my bank account. With forcasted war-time gas prices approaching $3.50 a gallon for the high grade stuff I would like to hear others thoughts on this topic. I apologize if this idea is offensive to some.

What would happen to my potential MC if I filled her with something less than premium?

Thanks

 

see, the way I see it, 91 octane is only about 20 cents more than 97. So after 13 gallons, you've saved $2.60. Hardly seems worth it to me .. You're still gonna be paying thirty bucks at these prices

 

I've noticed that the price difference between regular and premium is less as the price gets higher. When gas was 1.05 for regular, premium was 1.25. Now that regular is over $2, premium is often only 12-15c more, at most 20 cents more. You can put regular in the car, it will run fine, but it is tuned for premium and you will loose some performance - including fuel economy. YMMV.

 

to answer your question directly. yes the mini requires premium. the engine is set to work off that high octane, and if you use lower, then you could blow up your engine, which would be very bad. hope this helped.
jess

 

The octane rating is a value that is related to the fuel's tendency to self-detonate. The higher the octane, the less likely the fuel will detonate. This is important, since the MINI is a high compression engine to use a higher octane fuel, therefore balancing the compression-to-detonation values (basically). Using lower octane fuel will promote detonation during your compression stroke, and may cause damage to your valves or pistons (not a good idea). The MINI's computer will compensate for lower octane fuel (aka dummy headroom) by greatly reducing performance (in the form of power output and efficiency) to reduce the tendency to detonate.

Bottom line, use 91 or higher octane fuel!

Cheers,
Ryan

 

O.K. here we go...

Gasoline's ability to resist detonation is called its "octane" or anti-knock rating. All marketed gasolines are a blend of straight run and cracked gasolines, so unless their blending is controlled, the anti-knock qualities will vary.

A mixture of iso-octane, which has a very high anti-knock rating, and heptane, which makes a pronounced knock, is used as a reference fuel to establish an anti-knock standard. The anti-knock value or octane number is represented by the percentage of volume of iso-octane that must be mixed with normal heptane in order to duplicate the knocking of the gasoline which is being tested. These ratings range from 50 in third grade gasolines to 110 in aviational fuels. The rating of 100 means a fuel having an anti-knock value equal to that of iso-octane. If the octane rating of a gasoline is naturally low, the fuel will detonate as it burns and power will be applied to the pistons in hammer-like blows. The ideal power is that which pushes steadily on the pistons, rather than hammer against them. The octane rating of a gasoline can be raised by treating it with a chemical which is not a fuel. The best chemical known is tetra-ethyl lead compound, which is added to the gasoline as an "additive"

So to get to the point (finally) it will most def. have an effect on your engine, although you may not "notice" it. Over time engines that need the higher rating and do not get it will wear harder and quicker. We are talking long term, but conditions vary.

My advice (if anyone cares) is to get 91 or higher depending on your area. You will not notice a performance diff if you run a lower grade, the MINI is too "smart" to let us know. But... you will cause more wear and tear on the pistons, bearings etc.

The detonation is alot more then just an annoying sound. We spent all this money on a great,well engineered car, what's a couple of bucks at the pump? Trust the MINI. The MINI is good. Love your MINI

 

If you do a search of the forums, this has been discussed many times. Lots more good info to be had.

 

in the UK we only get fuel between 95-98 octane. so do we have higher quality fuel or is it measured differently?

 

Just a little note on the savings for a 91 octane MINI over other cars. We traded a small SUV that cost us about $26.00 to fill the tank. It got a respectable 19 miles to the gallon (for an SUV); so we filled the car about weekly. However, now we have a MINI, we still fill the car weekly and put in about $20.00 (on a bad day) in the tank. With the combination of the smaller tank and the higher gas milage; we are actually saving money in gas weekly and yet spending more per gallon. So you have to look what you spend today in gas versus what a MINI will cost...and then before you think to shove lower octane in the tank; remember what it could cost you in repairs or worse in gas milage!