S54 M engine, super or regular unleaded?

[martinb1966]

my mate was an engineer for Renault they ran engines on normal 95 and an unspecified 98/99 premium fuel they split the engines he showed me the pics - one black carbonised gritty , the other new metal , I am an engineer , I was surprised but not greatly , the old adage is true = you get what you pay for , you bought a bmw not a kia so why would you expect the lesser to be is as good as the better ?

 

[Zeld4]

my mate was an engineer for Renault they ran engines on normal 95 and an unspecified 98/99 premium fuel they split the engines he showed me the pics - one black carbonised gritty , the other new metal , I am an engineer , I was surprised but not greatly , the old adage is true = you get what you pay for , you bought a bmw not a kia so why would you expect the lesser to be is as good as the better ?

I like it when somebody posts a message like this which blows all the conspiracy theories (it's all the same petrol and they just charge you more) out of the water. If Shell's claims weren't true about what their premium petrol does then they would be taken to court and sued for billions.

 

[chasBMW]

I ran both my Z4mc's on 98 , as has been posted its what the manual recommends and any saving is going to be vastly exceeded by engine repair costs

 

[beanie]

The only time mine has ever run badly was from a tank of V-power. I reckon the price had put off so many people that what they had left was just very old dregs. Hardly a true reflection on the fuel but worth bearing in mind that as the prices rise the fancy petrol will not sell as well meaning it will sit in the forecourt tanks for longer.

 

[StevenH72]

The only time mine has ever run badly was from a tank of V-power. I reckon the price had put off so many people that what they had left was just very old dregs. Hardly a true reflection on the fuel but worth bearing in mind that as the prices rise the fancy petrol will not sell as well meaning it will sit in the forecourt tanks for longer.

Orrrrrr, it could just be that your ECU was adjusting to the new grade of fuel?

 

[exdos]

Orrrrrr, it could just be that your ECU was adjusting to the new grade of fuel?

It doesn't happen that way. Short Term Fuel Trims will make instant adjustments to a sudden change in fuel types as will the Ignition Timing Advance etc. For an explanation of Fuel Trims see here: http://www.obd-codes.com/faq/fuel-trims.php

 

[buzyg]

The use of 98 RON (mainly Shell Optimax aka V-Power) for 30k miles will not prevent bearing shell failure, ask me how I know! So IMO, anyone buying into this on the pretext of doing the best for your engine is misguided.

I'm no mechanic, but what has this to do with the RON of the petrol. :?

Back to topic, 97-98 RON in mine except for emergencies.

 

[exdos]

The use of 98 RON (mainly Shell Optimax aka V-Power) for 30k miles will not prevent bearing shell failure, ask me how I know! So IMO, anyone buying into this on the pretext of doing the best for your engine is misguided.

I'm no mechanic, but what has this to do with the RON of the petrol. :?

The answer to your question lies in my second sentence. Apologies if you don't find my comments interesting or even helpful.

 

[buzyg]

The use of 98 RON (mainly Shell Optimax aka V-Power) for 30k miles will not prevent bearing shell failure, ask me how I know! So IMO, anyone buying into this on the pretext of doing the best for your engine is misguided.

I'm no mechanic, but what has this to do with the RON of the petrol. :?

The answer to your question lies in my second sentence. Apologies if you don't find my comments interesting or even helpful.

Too criptic for me, Still :?

Any chance of a staight answer?

 

[exdos]

Too criptic for me, Still :?

Any chance of a staight answer?

In my initial posting I was suggesting that many owners (target customers of the likes of Shell V-Power), not necessarily members of this forum, buy in the belief that if they don't use such fuels, they are at greater risk of suffering engine damage, and since the subject of bearing shell failure was a "live" thread on this forum at the time I made the posting, I simply connected that particular aspect of known engine damage suffered by the S54 engine into this thread. Is this a straight enough answer for you? :?

 

[Darren Slone]

Too criptic for me, Still :?

Any chance of a staight answer?

In my initial posting I was suggesting that many owners (target customers of the likes of Shell V-Power), not necessarily members of this forum, buy in the belief that if they don't use such fuels, they are at greater risk of suffering engine damage, and since the subject of bearing shell failure was a "live" thread on this forum at the time I made the posting, I simply connected that particular aspect of known engine damage suffered by the S54 engine into this thread. Is this a straight enough answer for you? :?

That's better, thanks for the clarification

 

[StevenH72]

Orrrrrr, it could just be that your ECU was adjusting to the new grade of fuel?

It doesn't happen that way. Short Term Fuel Trims will make instant adjustments to a sudden change in fuel types as will the Ignition Timing Advance etc. For an explanation of Fuel Trims see here: http://www.obd-codes.com/faq/fuel-trims.php

Ok, fair enough.

Although, I have seen quite a few people on here say that it takes 1-2 tanks of fuel for the ECU to adapt to a new fuel type...is this all complete bulls**t?

 

[exdos]

Ok, fair enough.

Although, I have seen quite a few people on here say that it takes 1-2 tanks of fuel for the ECU to adapt to a new fuel type...is this all complete bulls**t?

IMHO, yes. I say this after doing a lot of datalogging of the DME and it shows that it can cope with just about everything you can throw at it.

 

[BMWZ4MC]

Higher octane fuel makes the car pull harder especially at higher revs. I've found the effect of different octane fuels is more apparent when stepping down to 95 octane fuel. The blunting of the performance is no more than that found from the addition of the weight of a passenger, but it is noticeable. I don't buy 99 octane fuel for its engine-cleansing additives or better economy, but for this reason alone.

 

[buzyg]

Too criptic for me, Still :?

Any chance of a staight answer?

In my initial posting I was suggesting that many owners (target customers of the likes of Shell V-Power), not necessarily members of this forum, buy in the belief that if they don't use such fuels, they are at greater risk of suffering engine damage, and since the subject of bearing shell failure was a "live" thread on this forum at the time I made the posting, I simply connected that particular aspect of known engine damage suffered by the S54 engine into this thread. Is this a straight enough answer for you? :?

Got it and after a bit of googling I know a tiny bit more about our lovely engine too. So good result.

 

[StevenH72]

Ok, fair enough.

Although, I have seen quite a few people on here say that it takes 1-2 tanks of fuel for the ECU to adapt to a new fuel type...is this all complete bulls**t?

IMHO, yes. I say this after doing a lot of datalogging of the DME and it shows that it can cope with just about everything you can throw at it.

thanks exdos....always helps to listen (and learn from) informed opinions