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Any recommendations on unleaded fuel to use in Cooper S? Previous cars I have generally filled up at Esso or BP and use their regular but when at Tesco will always use Super Unleaded Momentum99.

What are your thoughts on what to use in Cooper S?

Thanks
 

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Any recommendations on unleaded fuel to use in Cooper S? Previous cars I have generally filled up at Esso or BP and use their regular but when at Tesco will always use Super Unleaded Momentum99.

What are your thoughts on what to use in Cooper S?

Thanks
Shell v power for me :laugh:
 

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A couple drops of Jet Fuel might make your S fly.:D



I only have the 3 Banger and honestly I can not feel the difference between 89 or 91 Octane while under Load. Remember most of the Time the Fuel comes from the same Storage Tanks in your City anyway they just add some magic chemicals in the end into the Tanker Truck. So I always buy the cheapest Gas/Petro I can find. How I know all that. My Buddy hauls Fuel for a living and I have seen it many Times when he loads the Tanker. I believe it is an old Wifes Tail that one Brand is better than others.
 

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Definitely a performance difference between 89 and 91 (mid grade and premium US).
Well, if that's the case then... UK has it good!

In the UK, the most common petrol types are:

Ordinary unleaded – 95 RON
Super unleaded – 98 RON

You guys are on 89 and 91... :/
 

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Always been super unleaded since I bought it. Start as you mean to go on ����
 

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When I bought my 2010 Cooper hatch (in the UK) I used the expensive fuel exclusively for the first few months. Then I got fed up with idea and changed to regular. Never noticed the change.

Derek
 

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I did this whole calculation (for the UK) a while back..

So, if we take an average annual mileage of 12,000.

We assume that Super/V-Power/Momentum etc is 4p per litre more expensive (so £0.04 x 4.55 = £0.182 per Gal (Imp)) than 95RON Unleaded

We assume we all drive like ****ers most of the time so get around 30mpg

This means we'll use about 400 gallons of fuel a year (12,000 / 30 = 400... do keep up at the back)

So, making the "switch" to Super will cost you an extra £72.80 a year (or 6 quid a month) over 95RON.

To me, for the benefits to the engine and cat, this makes sense... To others, it may not...
 

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I'm not convinced and on a direct injection engine valves can't be cleaned by the fuel so v power benefits not really applicable to our cars hence part of the Cooper s r56 coking issue plus of course the oil recirculation circuit. I always buy cheapest and it add a suited my mr2 which was sweet as a nut at 160000 miles when I sold it. You might get a slight power gain ,my brother reckons 1or 2 mpg more.

Americans have it better have you seen the price of fuel over there!
 

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I'm very dubious about the "cleaners" in fuel anyway, I'm more interested in higher octane reducing pinking and the associated effects.
 

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Well, if that's the case then... UK has it good!

In the UK, the most common petrol types are:

Ordinary unleaded – 95 RON
Super unleaded – 98 RON

You guys are on 89 and 91... :/
95RON is equal to 90-91AKI or (R+M)/2. US and Canada both use the AKI standard, which is just a different test for fuel. It averages the RON rating that is used in most of the world with the MON rating to give an "Anti-knock Index" number. As far as I can tell our fuel is the same as Europe's. Example: The station just down the street from me has 101RON fuel (94AKI).
 

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Which? magazine tested premium fuels* and found that they had no benefit on ordinary engines, but were useful on turbocharged engines, where some of them actually made financial sense (ie, fuel economy gains greater than the extra cost). Now that even the (dare I say it?) justa Cooper is turbocharged, that may benefit from premium fuels.

The great problem is that it's almost impossible to measure the difference accurately enough to see if they are worth it. Some people confidently say they get X mpg better from premium fuels but then I think they believed that before trying them, so all they are really saying is that they believe the evidence fits their pre-conceptions - which it always will, even if it's not true! To give a real test, total fuel consumption over a year would be necessary - but then is that measuring that one winter was mild while the other was severe?

Just look up double-blind testing which is used on medicines - it shows the length it's necessary to go to to avoid getting a result that isn't just the tester's bias.

* that should be premium petrols/gas - they tested premium diesels and found they were often worse than regular diesel!
 

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Unfortunately, the Which? report only identified and focussed on one area of the benefit of high(er) octane fuels. With forced induction pinking or knock is much more likely so using too low an octane can (I'd say will, but I'm trying to be unbiased) cause damage on a molecular level to the internals of the combustion chamber and adjacent areas (water/oil channels, camshaft bearings, valve guides etc al) because of the early detonation "shock wave" effect.

Modern engines have a knock sensor (or many) listing for this and will when it can, advance the injection timing to compensate, but this will effect your efficiency of the 4 stroke cycle as there is always an "optimum".

The farther up the performance curve you go, the more important this becomes. I would advise anyone with a JCW, and probably MCS owners to choose a higher octane fuel if they can, but if you are as finicky as me engineering wise, you probably do anyway. If you modify your car other than simple exhaust/induction, most tuners would insist on it to protect their hard work and maximise your gains.

As for diesel, well. This is my area of real (read: professional) expertise although somewhat outdated (I stopped being a professional oily person before 2000), but nevertheless, I have a degree in Engineering (Marine) and spent many years hitting 30,000hp engines with hammers.
So, to my point. A diesel engine will burn pretty much anything once it is warm as long as it's slightly volatile so the "quality" of DERV is somewhat of a misnomer. However, the crunch comes with modern diesel cars as they have a number of factors that require a "nice" fuel.
Audi and BMW are particularly good as getting magnificent performance and efficiency from their TDi's, and this is primarily down to the dynamics of their injectors and the atomisation of the fuel they produce in the combustion chamber, and this is 90% down to the injector nozzle itself.
When your engine is COLD, DERV is an unfriendly liquid and takes real encouragement to burn, hence glow plugs etc. If your injector nozzles are dirty and gummed up, this will be harder and you'll get big, fat droplets (relatively) rather than the superbly engineered mist engineers like me love. This can cause a "lean" burn at start up and this can put real strain on your valve seats over (admittedly pretty long periods of) time. So, DERV with cleaners in help prevent this. It would be better if they said "V-Power Diesel maintains your engine's efficiency for longer" as this would probably be a more accurate statement!


There you go, that's my lesson, shoot me down at your will!! :)
 

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That's brilliant and very interesting. Not keen on diesel myself but v useful to know.
 

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I have a degree in Engineering (Marine) and spent many years hitting 30,000hp engines with hammers.
Ah, proper diesel engines - with doors in the crankcase to climb inside and ladders to get you from crankshaft to cylinder head level.

And consuming something like warmed-up tar used in a road-laying machine.
 

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Ah, proper diesel engines - with doors in the crankcase to climb inside and ladders to get you from crankshaft to cylinder head level.

And consuming something like warmed-up tar used in a road-laying machine.
Yup, pretty much. The ladder will only get you to the bottom of the two metre long cylinder bore though. Most people don't get the scale of marine slow speed diesels. And yes, the fuel (M1) is a bit, ummm, sticky. We clean it (filters and centrifuges) and inject it once it's been heated up to 130-140 deg c. (memory's getting a bit hazy, think it was about that)...

Halcyon days...
 
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