So I have the 2002 R53 and have been running 87 octane for the 7 months and learned that it is not what it needs...so what are the differences and what should I run
I have SHELL 91 with 0% Ethonal or BP 93 with 10% Ethonal

I am wondering should I have the better octane or no ethonal
Thanks

 

It really depends on the history of the car and the mileage.
The reason I say this is that on a factory tune the difference between 91 & 93 will be minimal, but the ethanol in the 93 may loosen up some rust or deposits in the fuel system if the car wasn't maintained that well, since ethanol acts as a cleaner for your fuel system as well.

 

ok well I have done none of these mods but the car as 131,000 miles, MSD Coils/Ignition, Alta Air Intake and a supercharger pulley.
So that is what I know

 

I also keep up on checking all fluids and oil changes every 5k

 

Since it has a pulley, and with that mileage, I'd just go ahead with the 93 + ethanol, the motor will appreciate the extra octane, and in reality the risk of clogging up the fuel system is minimal.
If you didn't have the pulley, it would probably be the other way around, simply to err on the side of caution

 

ok thanks I think that is a little cheaper as well

but since I dont know how long the vehicle was run on 87 will it be bad if i keep using it becuase it cost me $10 more each complete fill up which is kind of a lot

 

I wouldn't, while it is winter and the possible damages are lessened, it's still normally a bad idea because of possible detonation/pinging, which can really damage a motor. WIth the pulley you're increasing the odds of doing damage, every time you would accelerate hard, even more .

 

ok well we will see how much better mpg i get because im getting 22 at the moment and I drive 70 on the freeway each day to work and home and thats really it

 

In a nut shell, I was giving my advise on performance and safe operation of the motor.
If cost is your driving factor, choose which ever is cheaper between the 93 & 91, but definitely stop using the 87 as soon as possible.

 

ok thanks for the help today I ran it down as far as I dared so I could get as much new fuel in...I put the 91 today so then maybe Ill switch to the 93 see what mpg I get from both
Thanks

 

just realized I had .1 gallons left in the tank because I filled it with 13.1 gallons!!

 

You will get better mpg with the 91 ethanol free. Ethanol has less BTU/gallon than gasoline. I have a choice between both gasses and I choose the ethanol free. Ethanol does horrible things to older fuel systems. The car is built to run on 91 so there is no benefit for 93 unless you have a time specifically for that octane. As long as you are driving the car on a regular basis and not letting it sit, the 93 ethanol is fine. Sitting and storage for a car with ethanol gas is a big no no.

 

I normally run 93 10% ethanol in my cars since they have it at my local station. A few times I went out of my way to find some non-ethanol 91 to see if it ran any better. I actually noticed a little bit of pinging with the 91....I never get it with the 93 10% ethanol.

93 octane is 93 octane...doesn't matter if it's got ethanol in it or not. If you are running a pulley and making more boost, run the 93. In my area, the 91 non-ethanol is more expensive than the 93 10% ethanol.

 

ok perfect 2 different answers...thats ok I can get the 91 e free for $.10 less a gallon but what Ill do is use the 91 3 tank fill ups and then switch to the 93 and see if theres any difference in mpg/performance/and engine smoothness

 

So I have not noticed any difference in using the 91 e free fuel and don't know if I want to use it right now..It may not have cost this much back 2002 but it cost over $.70 more cents a gallon and almost $15 a fill up..I have to fill it at least once a week and that is crazy expensive which I can't afford and have not noticed anything better or worse with the premium fuels. I can almost garentee that they way the car looked when I bought it used the guy probably put the cheapest stuff in so do u think that I will be fine because I don't see any difference except the hole in the wallet.

 

And by $15 a fill up I mean more so nearly $38 a tank each week almost.

 

Meh, 91 E free versus 93 ethanol, either one you will be fine with. As someone stated octane is octane. But I have noticed that most of my vehicles after running a few tanks of E free I do notice enough of a mileage increase that it may be more per gallon, but I'm getting more miles per dollar the increase in mpg is so much better.

BUT, the e free I have available is 93, so I have a choice of E free or ethanol both at the same octane.

Either of you're choices will be fine for the vehicle though, just make sure you run premium. Ethanol won't hurt the car per say, but you can get better mpg from E free, it's just down to is it available cheap enough for you to be saving money that way.

Instead of seeing which one gets more miles per gallon, see which gives you more miles per dollar. That will be the best to use for you.

 

So are you saying you are just going to run 87 fuel in your Mini? If so...that's a bad idea. Just because you "don't notice anything" doesn't mean that it's not damaging your motor. There is a reason why is says run a minimum of 91 octane in the manual.......

 

No necessarily but what I'm saying is that I'm sure the car was run for most of its life (judging from the state of the guy I bought it from) on the cheapest stuff and I don't know how it could be worth $40 fill up when it's my daily driver and need to fill that each week.. but I know what the manual says but what I'm wondering since the car isn't getting any better mpg would the car of just gotten used to running the 87 or 89 from the years prior.
But I will run premium for now and thanks for all of the input

 

I just saw where you said you are only getting 22mpg, that's pretty low for these cars. I get 32mpg average. The years of 87 might have already taken its toll on performance. The motor and the computer are tuned to run on premium. Anything lower is just going to make things worse.

 

Ok ya I understand and I know if have no place in say because I have had a mini for only about 7 months but with that would there be things to help get my mpg back up. Such as resetting computer, changing spark plugs possibly, fuel filter, etc. or anything else that may improve because I know by now the engine is completely free of the 87

 

Plugs might help if never changed. Just stick with the premium and see what happens.

 

ok thanks I am taking to my nearest mini dealer probably end of the week (even though nearest is nearly 2 hrs lol) because I need some new keys hooked up but I want to have the service drive it on the freeway I really want to know if how the engine sounds now if that is how it is suppose to be or if a component is starting to go because I dont know for sure what is all good or really bad because I honestly dont have any history with superchargers...even though it is awesome