[Garry]

What experiences have MINI owners had with the different octanes for petrol?

Does the higher octane 97 RON improve performance and fuel economy?

Can you run Shell Optimax 100 RON in the MINI?

Which brand of petrol is 'best' or doesn't that matter?

[monsta]

I have used 97 RON and I don't think it made any difference. Except it was really expensive. The fuel economy might have been better but it costs more so therefore you get less miles for your money.

[AER]

Is the MINI designed to run on 95 or 97? today's cars are sorted to run on the lower octane, but older ones rely on a higher rating.
The car I use everyday, needs 98, I was using normal 97 super unleaded, but as soon as 98 Optimax came out, I switched to that and felt an instant improvement. But I doubt you will need it in the MINI.

[Racer]

Have to agree with AER - Current car needs 98 + RON but I run it on 97 difference is noticeable BUT trying finding 98+ on a constant basis when a tank only takes you 240 miles isn't easy ! - Some of the garages I've been into don't even have Super U or they've run out 'cause they've only got 1 pump of it !

[daxler]

I've been filling up with optimax over a couple of weeks and have noticed a very slight improvement in the tickover ( slightly lower and generally slightly smoother ) but it is very slight and I just fill up with regular unleaded when there is no shell station about. If its there i'll use it if its not it's fine without.

[Ibb]

I've heard that it is possible to mix the 2fuels together, supu u and nor u.

U can get super unleaded form sainsbury's fuel stations, and if u have a reward car it helps on the cost effecient side.

I guess it depends on who you buy from. When my MINI arrivess on the 6th of Feb, I shall definetly get my Super Unlead from Sainsbury's, as I have a reward car, and hope fully that should compensate in the long run.

Oh it cos 78.9 per litre at my local Sainsbury's station.

I'll make sure mixing the 2 fuels is safe tho, if it is the this option would be even more cost efffective.

Cheers everyone

[Johnboy]

Quote:

Originally posted by Garry
What experiences have MINI owners had with the different octanes for petrol?

Does the higher octane 97 RON improve performance and fuel economy?

Can you run Shell Optimax 100 RON in the MINI?

Which brand of petrol is 'best' or doesn't that matter?

Standard unleaded is fine, but given that I only get about 8 gallons per fill, the extra GBP1.50 for Optimax is so little I nearly always fill with it....

It's supposed to clean your valves too. I intend on doing a 1 in 3 of Optimax at the very least, just in case it really goes keep the valves clean, and just in case that makes some sort of difference

I find my car starts better and is smoother at low revs with Optimax. There is a very marginal improvement in performance too.
One of the other threads suggested the diff. would be greater in hotter countries/summer time because detonation is less likely to occur with higher Octane fuel, so the ECU would be able to advance the timing that bit more, relative to 97RON. Roll on Summer - Now where's that sunroof switch gone

Incidentally what's that horrid 91RON stuff that comes as the standard fuel in N.Z... Total pants! It should be relegated to use by moped riders and dumper trucks!

[My MINI me and me]

Quote:

Originally posted by Johnboy

Standard unleaded is fine, but given that I only get about 8 gallons per fill, the extra GBP1.50 for Optimax is so little I nearly always fill with it....

It's supposed to clean your valves too. I intend on doing a 1 in 3 of Optimax at the very least, just in case it really goes keep the valves clean, and just in case that makes some sort of difference

I find my car starts better and is smoother at low revs with Optimax. There is a very marginal improvement in performance too.
One of the other threads suggested the diff. would be greater in hotter countries/summer time because detonation is less likely to occur with higher Octane fuel, so the ECU would be able to advance the timing that bit more, relative to 97RON. Roll on Summer - Now where's that sunroof switch gone

Incidentally what's that horrid 91RON stuff that comes as the standard fuel in N.Z... Total pants! It should be relegated to use by moped riders and dumper trucks!

Shell's Optimax rings alarm bells in my head regarding the debarcle with Formula Shell in the late 80's. Didn't that ruin the valve seals on Vauxhall engines amongst others. I know it's 10+ years on but does anybody know what Shell has done to avoid simular problem. At the moment I turn various shades of red whenever my gilrfriend says "the only Super Unleaded I could find was Shell Optimax, but don't worry I filled up the tank for you".

[AER]

I don't think you'll ever know the answer to that question.
As you say that was 10 years ago. But then again, they all said we had to run on unleaded for the environment etc, but now it has been proven that unleaded is just as bad, if not worse than leaded. More toxic during the first 15 minutes whilst the cat warms up than normal 4star was.
I use Optimax in my car, it's smoother, mid range punch has been noticably improved, it sound better to.

[JV]

To answer an earlier question from AER the hand book says anything from about 93RON to 100oddRON I think, BUT here's a thought...

On the Impreza at least when you use 95 RON the ECU switches the timing to be suitable for that fuel BUT when you refill with 98 it won't switch back coz the ECU has a memory and will always stick with the safe bet SO if you intend to use the higher grade fuel on a Scooby ALWAYS ALWAYS stick with it, otherwise you have to unplug the battery and other messy stuff like that...

On a slightly different tack, can you open the doors on the MINI with the battery off - how will the windows come down?

[Garry]

Quote:

Originally posted by Johnboy

...
Incidentally what's that horrid 91RON stuff that comes as the standard fuel in N.Z... Total pants! It should be relegated to use by moped riders and dumper trucks!

The 91RON is the regular unleaded in Australia as well. From memory the highest octane is 95RON - called Premium Unleaded. The cars run OK on 91 but if you have a reasonable car you need to use the higher octane.

I have filled up with Shell Optimax 98RON in my 300 mile old MINI. Seems OK, but I haven't noticed any improvement in power or economy. I figure that the car is too new and needs to be run in for a few thousand miles.

[Johnboy]

Quote:

Originally posted by Garry


The 91RON is the regular unleaded in Australia as well. From memory the highest octane is 95RON - called Premium Unleaded. The cars run OK on 91 but if you have a reasonable car you need to use the higher octane.

I have filled up with Shell Optimax 98RON in my 300 mile old MINI. Seems OK, but I haven't noticed any improvement in power or economy. I figure that the car is too new and needs to be run in for a few thousand miles.

Yeah, at 300 miles, my engine (in relative terms) was "as tight as a gnat's ass"! It started to noticably loosen up at about 600 plus and now after 3k seems to be bedded in nicely....
Yeah, I tried some 91RON in a Ford Ka whilst out in NZ, and the car pinked itself to death on the hills around Auckland!
Would love to go back and tackle those roads in a Cooper

[Alex]

I too have used Shell Optimax, first time was at about 2,000 miles and didn't notice much difference. Recently used it again at about 6,000 miles and it has made a difference. On Saturday I put in Texaco Super unleaded into an empty tank (0 miles on trip computer for ten miles!) and it really seems to have made a difference. Not sure about the economy but it is faster and to my ears a bit louder when putting foot to the floor. Also maybe its my imagination but it seemed to rev faster as well, quicker upto the 4,000 mark where the fun begins! To me the extra cost is worth it for that little bit extra performance.

[howieb]

Quote:

Originally posted by Alex
I too have used Shell Optimax......0 miles on trip computer for ten miles

Blimey, you're treading dangerously aren't you? I start to panic at 30 miles on the computer but maybe its more conservative than I thought. I have heard that letting a tank go right down to empty can wreak the catalyst.

[chiph]

For US readers:

The pump octane (PON) listing we see at the gas station is the average of RON and MON numbers.

PON = (RON + MON) / 2

The UK uses RON (Research Octane Number) on their petrol pumps. MON (Motor Octane Test) is a number created from a different testing standard than RON. So for the UK's 98 octane, which has a MON of roughly 90, it would correspond to a PON of 94.

You can read more at: http://www.btinternet.com/~madmole/R...RONMONPON.html

And, as long as we're talking about your favorite gas/petrol: I like Amoco (now BP) Ultimate @93PON.

Chip H.

[snoopy]

Here some thoughts on the Ron of petrol from a person that has the Ron 91 stuff.

Here in Oz the normal unleaded is Ron 91. Yes the engine does ping and the cars can perform like dogs.

Most of the cars that come in from Europe have a warning label fitted to the fuel filler to tell you that premium unleaded is required. In Oz premium unleaded means a Ron 95 and above.

You do get better performance from the car when it is run on a higher grade fuel. My work car (a Holden Commodore (OZ car, 4 liter 6 cyl, large family car )) dinks the petrol but after using the better fuel for about a month the car got better fuel economy and was more responsive. So the extra range I get out of a tank of fuel offsets the extra 6-cent per liter at the pump.

Also have a talk to your MINI repairer, as they might be able to tell you a way to get the computer to retune it. One car required me to rev it between 2000 to 6000 (7500 redline) ten times and then ECU then adjusted the timing. Also I found that I had to use about 3 tanks of fuel before any great difference was noticed.