95 octane fuel - ECU reset?

[Wollemi]

I always use super, nearly always Shell V-Power, in my 987.2 Boxster S. Now I don’t want to start yet another discussion of whether this is a good thing or not.
I understand that if I use normal (95) fuel then the engine management will adjust so that the car runs fine with no problems
What I want to know is does the engine management automatically readjust when I go back to using super unleaded?
Years ago, when I had Subarus they had to go to the dealer to have the ECU reset once normal fuel had been used.
Is the Porsche engine management more sophisticated- will it sort itself out or will it have to be reset?
Will simply disconnecting to battery be enough to reset it?
Thanks

 

[RCS]

I always use super, nearly always Shell V-Power, in my 987.2 Boxster S. Now I don’t want to start yet another discussion of whether this is a good thing or not.
I understand that if I use normal (95) fuel then the engine management will adjust so that the car runs fine with no problems
What I want to know is does the engine management automatically readjust when I go back to using super unleaded?
Years ago, when I had Subarus they had to go to the dealer to have the ECU reset once normal fuel had been used.
Is the Porsche engine management more sophisticated- will it sort itself out or will it have to be reset?
Will simply disconnecting to battery be enough to reset it?
Thanks

My understanding is the ECU adapts both ways so no need to visit a dealer. We had a 997.2S usually on 'super' but went on a trip to Southern Ireland - all 95 over there nothing higher sold - it ran fine both over there and back here. So I would not worry.

As an aside and interestingly when we bought the 997 from an OPC not being local I asked if the local Sainsburys down the road was the nearest for super unleaded, answer was no idea we run everything on 95!!

 

[Richard_Hamilton]

I don't know if it works on the 987.2, but on a 986 and 987.1 you can reset the adaptation values to the factory setting. Switch on the ignition for 60 seconds, during which time you must not touch the throttle pedal. Then switch off the ignition for at least 10 seconds.

 

[JMR]

As said above.
I usually use 99 V-Power.

I have used 95 on a few occasions and I notice no difference whatsoever.
No extra power, no more economical, just a few extra quid extra to fill up.

I'm not saying it won't be slightly better after a few tanks full vs a few tanks full of normal 95.

 

[Brian_Innes]

Using super premium fuels such as Shell V-Power is not only about performance gains.

Using a 99 Ron fuel in your Porsche allows the ECU mapping to advance the ignition timing for a more efficient and cleaner burn. This is particularly relevant on DFI engines where lower Ron fuels can cause a build-up of carbon deposits on exhaust valve stems which can ultimately lead to more serious problems.

Super premium fuels also contain detergent additives and lubricants which further improve the longevity of the engine.

It's not simply a case of "the car runs just the same on 95 Ron fuel". It's what goes on inside the engine during the suck, squeeze, bang, blow, cycle that separates the 95 Ron from the super premium alternatives.

Brian

 

[JMR]

Using super premium fuels such as Shell V-Power is not only about performance gains.

Using a 99 Ron fuel in your Porsche allows the ECU mapping to advance the ignition timing for a more efficient and cleaner burn. This is particularly relevant on DFI engines where lower Ron fuels can cause a build-up of carbon deposits on exhaust valve stems which can ultimately lead to more serious problems.

Super premium fuels also contain detergent additives and lubricants which further improve the longevity of the engine.

It's not simply a case of "the car runs just the same on 95 Ron fuel". It's what goes on inside the engine during the suck, squeeze, bang, blow, cycle that separates the 95 Ron from the super premium alternatives.

Brian

Quite right Brian.
My usual fill up is Shell V Power 99, which is my nearest fuel station to home.

My nearest fuel station at work if I'm a bit low is Sainsbury's, so every now and again I stick their Superunleaded in.
Mainly go Shell though.
As you say, I've always been 'sold' on the cleaners that Optimax/V-Power/Nitro/V-Power has in it.

 

[Leaperslair]

Having worked in the fuel industry it may surprise some to know all the supermarkets and shell,Esso, etc pull fuels from the same terminals additives are the same !

 

[mr pg]

We were recently in Italy in our 981 CS. Unable to find anything other than 95, and the car didn't like it at all. Accelerating from speeds in gears I'm used to started to induce pinking we've never experienced elsewhere. Had to change my driving accordingly. Much as we love the lakes/Dolomites, I was glad to find decent fuel on leaving Italy.

 

[Madala]

Was that on just one fill up or multiple fills? ........ If it were just the one it could have been contaminated fuel.

 

[Mark_collin1977]

We take our 987.1S down to Rome every summer and never had any issues with the fuel in Italy despite there being no super. I will add that I normally go via Germany in search of 105 octane you can get there which does feel more responsive in the car.

 

[Motorhead]

Paul,

Like all modern engines it has knock-sensors which should signal the DME to retard the ignition sufficiently to eliminate the pinking you describe.

Are you certain that yours are functioning correctly?

Jeff

 

[Wollemi]

Having worked in the fuel industry it may surprise some to know all the supermarkets and shell,Esso, etc pull fuels from the same terminals additives are the same !

My understanding that that is true for most fuels but does not apply to Shell V-Power.

 

[Motorhead]

There can't be that many fuel supply terminals in the UK and I'm sure I read that although the base fuel is the same, the premium fuel suppliers - BP, Shell, Esso, etc. - include their own additives at the tanker filling stage.

It's the proprietary additives that separate the premium suppliers from the supermarkets, who also have their own additive mix.

Jeff

 

[russeldavies]

Just bought a cayman S gen 1 from a well known dealer, thru categorically stated that no need to use higher octane fuel and suggested that in there opinion the higher octane fuels might promote bore scoring? Any thought?

 

[Motorhead]

Russel,

I've never heard that one before. Was this just "salesman talk" or did it come from someone who could back-up the statement from detailed experience?

Although you can use 95-octane fuel in your Cayman without problems (the knock-sensors will take of of the ignition), higher octane fuel will release slightly more power if you're after ultimate performance from the engine. Super unleaded fuels are more expensive and often use additives not always included in 95-octane fuels.

Well done on your new acquisition and hope you're enjoying driving it.

Jeff

 

[911hillclimber]

Just to add, 987.2 2.9, never on a track, used for good cruising, odd stretch when driving solo.

Now on my 5th tank of Shell 95 after advice from one with knowledge. all is well, runs great, notice no loss in performance and flexibility etc.

The car simply feels the same as with Shell 99 in it TBH, but I stress I don't thrash it at all.
Graham.