In New England, the gasoline formulation is “tampered with” by government a couple of times each year; in the past this has caused the famous “cold start” issue in MINIs I have owned [note though that the “cold start” issue is named for the cold engine, and has nothing specific to do with air temperature!]
MINI USA has released many engine software updates since sales began in 2002, and none of them have solved the issue – the current software is considered to be “as good as it gets” for the current engine.
There have been many suggestions as to how to resolve the issue, popular ones being:
– turn key to position 2 and wait 5s before starting,
– use a lower octane gasoline.
Last year experimentation determined that the 5s key wait was no help, but GBMINI#3 was very happy with Sunoco 91 gasoline and I’ve been using it ever since.
However, my last tank of Sunoco 91 brought back the cold start issue – not as drastic as before, but noticeable. GBMINI#3 would start but run rough for a couple of seconds, and yesterday evening it stalled for the first time ever, while waiting to pull out of work.
There’s been some discussion about this on MINI2, so I decided to try an ever lower octane – I filled up last night with 89 from a local Mobil station.
This morning, GBMINI#3 started fine, and all day has been driving “more peppy”, seeming keener to pull – hard to say if it’s just my imagination … I’m not yet ready to claim “89 is the way to go” but we’ll see as this tank gets used.
Of more concern is the information online about adding 10% ethanol to USA gas, which is presumed to be the cause of all the recent “cold start” troubles here in New England. For example:
Alcohol fuel blends in MINI vehicles (MINI TSB M130106 from March 2006) includes:
… fuels containing up and including to 10% of ethanol … will not void warranties … usage of such alcohol fuel blends may result in drivability, starting, and stalling problems …
Top Tier detergent gasoline in MINI vehicles (MINI TSB M130206 from April 2006) includes:
… recommends using Top Tier gasoline of minimum octane rating AKI 91 and with alcohol content of less than 10% …
[note this does not say “less than or equal to 10%”!]
EMS2000 Various Software Improvements (MINI TSB M120206 from April 2006) includes:
… cold start problems may also be created by using fuels with a high percentage of ethanol (10% and higher). In such a case the DME is not able to fully adapt to non-conforming fuel volatility …
[here again, 10% ethanol is included in the “bad” range!]
(information on many BMW & MINI TSBs – technical service bulletins – can be found here)
I was talking to someone today that told me of some MINI issues MUCH worse than just poor starting when the engine is cold – apparently a number of MINIs (as well as other car manufacturers) have had fuel pumps destroyed by the new gasoline formulation! It seems that if there is any water or other contamination in the car fuel tank or even in the gas station tank, the resulting mixture can be very corrosive!
It seems crazy that MINI can claim their engine is designed for use world wide, yet by their own admission it’s incapable of working properly with USA gasoline (which is hardly a rare commodity)
Anyway, to summarize: if you are having poor engine start or rough idle issues when your MINI engine is cold, try filling up with 89 gasoline instead of 93; it might help.
M&I / GBMINI 
The biggest concern with the introduction of ethanol in New England, especially with all this rain, is poorly maintained underground storage tanks.
Gas stations have generally not worried about anywhere up to a couple of inches of water in their tanks because it just sat on the bottom, but ethanol will instantly separate from the gas and can lead to upwards of 10 inches of an alchohol water mix in the tank. The pick up is usually 4-6 inches off the bottom, so this can lead it big trouble ig you happen to pump this into your car.
In addition it is vital that the filters in individual gas pumps at the station be changed once the first load of ethanol blended fuel arrives.
Unfortuanelt many stations may not know when this is, so they won’t have cleaned the tank ensured there is no water and changed the filters.
10% ethanol blended gas should be fine, but there are so many places in the process where trouble can start.
One other: ethanol has to be blended at the distribution terminal (it is too corrosive to be piped with the gas, it must be trucked or rail-shipped). This means that each delivery tanker could theoretically have a different percentage of ethanol depending on how dilligent the person was doing the blending for that load….
Wow – thanks for all that great info! No wonder there’s been a few issues 😦
Usauss or others, how long should we run the 89 octane, all summer until the winter formulation?
And, should we add a fuel additive? Isn’t there one to remove water from the tank? Or am I imagining things?
People in the midwest often say they don’t have any problems – ethanol has been used as an oxygenate out there for some time so that is good news for the longer term.
Theoretically, anyone with badly maintained equipment will know about it pretty quickly, so the problems should be worked out in a matter of weeks. But keep in mind if the delivery tanker driver isn’t careful with the spill cups after a rainstorm, or someone screws up the ethanol blending process, problems could crop up at any time. If you know about it, I would avoid filling up right after a delivery. also, if a pump runs real slow – that is a sign that the filter in it is plugged (bad maintenance).
I think 89 octane helps because fuel over blended with ethanol will lead to a lean mixture particularly at idle or wot. The 89 helps to make the fuel burn a little faster and thios helps overcome that problem.
Well this morning, GBMINI#3 is back to a sluggish cold start and rough running for a few seconds – the 89 gas was only a short term fix 😦
Just started happenening to my 05 S, Zippy2, Symtoms are the same….tried the same….added some 87 to my tank full of 93….was ok for a couple of starts…but did seem to run better!?
was up at MOP today, a) they flashed my DME to 21.2 and Chris recommends running 89 (minimum, not 87) Shell or Texaco every other tankful…
so I started the car this AM and same old story, had to turn it over a 2nd time. Should be filling up w/ Shell 89 tonight/tmrw…
From this MINI2 post:
Under certain environmental conditions, mainly lower ambient temperatures, ethanol separates from gasoline/alcohol mixture and absorbs water. The ethanol absorbed water molecules are heavier then gasoline or ethanol, they remain at the bottom of fuel tank and when introduced into combustion process they tend to form an extremely lean mixture resulting in misfire, rough idle and cold starting problems