E10 fuel

[mueslibrown]

My bad ... didn't go back through the thread ... I'll try better next time ...

[On-Track]

I've used E10 in my previous 2 cars especially when driving in France. I was planning on doing the same with my upcoming GTS but every 4/5th visit to the pumps fill up with Premium quality. Good idea?

Porsche recommend 98 Octane fuel for the 2.9L engine (in both S & GTS) with 95 as a backup so you're unlikely to harm the engine by using 95 octane (which is E10). There will be some drop off in performance but I doubt you'll notice it in normal driving.

Having said all that, I run my GTS normally on Esso Supreme + (99 Octane) or, if Esso is not available, Shell V Power or BP Ultimate as I like to stick to Porsche recommendations.

[PorscheMack]

I've used E10 in my previous 2 cars especially when driving in France. I was planning on doing the same with my upcoming GTS but every 4/5th visit to the pumps fill up with Premium quality. Good idea?

Porsche recommend 98 Octane fuel for the 2.9L engine (in both S & GTS) with 95 as a backup so you're unlikely to harm the engine by using 95 octane (which is E10). There will be some drop off in performance but I doubt you'll notice it in normal driving.

Having said all that, I run my GTS normally on Esso Supreme + (99 Octane) or, if Esso is not available, Shell V Power or BP Ultimate as I like to stick to Porsche recommendations.

[Deleted User 4752]

Inside fuel filler cap on a 2022MY Macan S with 2.9L engine. Doesn’t seem to suggest not using E10, although the octane rating is written in a smaller font.

For ref I’ve only used the 99 Tesco E5 stuff.

[pmg]

Inside fuel filler cap on a 2022MY Macan S with 2.9L engine. Doesn’t seem to suggest not using E10, although the octane rating is written in a smaller font.

For ref I’ve only used the 99 Tesco E5 stuff.

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and I get same Mpg on Momentum 99 as on the Esso 99 and better than on V power that contains some Ethanol

[GWL]

Inside fuel filler cap on a 2022MY Macan S with 2.9L engine. Doesn’t seem to suggest not using E10, although the octane rating is written in a smaller font.

Once they've sold you the car, they don't care about whether you get the best out of it. So, E5, E10, 98 Ron. 95 Ron, it's up to the owner.
I just can't understand anyone buying a Porsche and running it on sub-optimal fuel. Seriously - spending approx £70k (+/- £15k) car, and then worrying about spending an extra £5 filling up is ridiculous.

[Bluesnose1812]

My understanding is that E rating and Octane are different animals. Octane relates to an engine's propensity to pink ie predetonate. Ethanol is simply the amount of organic fuel as a percentage of the total.

All engines are tuned to use fuel of a certain octane. In the UK all manufacturers tune to 95 octane and use E10. Using a higher octane has no effect on performance or consumption. If a lower octane is used then pinking can occur and can be rectified by retarding the ignition. Today that would require a remap. So conflating the two is meaningless. In fact pure ethanol has a higher octane rating than petrol.

[pmg]

My understanding is that E rating and Octane are different animals. Octane relates to an engine's propensity to pink ie predetonate. Ethanol is simply the amount of organic fuel as a percentage of the total.

All engines are tuned to use fuel of a certain octane. In the UK all manufacturers tune to 95 octane and use E10. Using a higher octane has no effect on performance or consumption. If a lower octane is used then pinking can occur and can be rectified by retarding the ignition. Today that would require a remap. So conflating the two is meaningless. In fact pure ethanol has a higher octane rating than petrol.

Some modern vehicles like Porsche and BMW's have flexible ignition control systems that although running safely on 95 octane allow the potential higher power/burn output of 98/99 to be obtained if used

[Bluesnose1812]

My understanding is that E rating and Octane are different animals. Octane relates to an engine's propensity to pink ie predetonate. Ethanol is simply the amount of organic fuel as a percentage of the total.

All engines are tuned to use fuel of a certain octane. In the UK all manufacturers tune to 95 octane and use E10. Using a higher octane has no effect on performance or consumption. If a lower octane is used then pinking can occur and can be rectified by retarding the ignition. Today that would require a remap. So conflating the two is meaningless. In fact pure ethanol has a higher octane rating than petrol.

Some modern vehicles like Porsche and BMW's have flexible ignition control systems that although running safely on 95 octane allow the potential higher power/burn output of 98/99 to be obtained if used

How does the engine know what octane fuel is in the tank? Why aren't performance and consumption figures shown for different octanes? I thought the compression ratio was the main determinant of power output all other parameters being equal. To get more power more fuel would be burnt and consumption worsen. I can understand turbo boost could be used but there must be an input somewhere to change it.

[pmg]

My understanding is that E rating and Octane are different animals. Octane relates to an engine's propensity to pink ie predetonate. Ethanol is simply the amount of organic fuel as a percentage of the total.

All engines are tuned to use fuel of a certain octane. In the UK all manufacturers tune to 95 octane and use E10. Using a higher octane has no effect on performance or consumption. If a lower octane is used then pinking can occur and can be rectified by retarding the ignition. Today that would require a remap. So conflating the two is meaningless. In fact pure ethanol has a higher octane rating than petrol.

Some modern vehicles like Porsche and BMW's have flexible ignition control systems that although running safely on 95 octane allow the potential higher power/burn output of 98/99 to be obtained if used

How does the engine know what octane fuel is in the tank? Why aren't performance and consumption figures shown for different octanes? I thought the compression ratio was the main determinant of power output all other parameters being equal. To get more power more fuel would be burnt and consumption worsen. I can understand turbo boost could be used but there must be an input somewhere to change it.

The sensors that monitor pinking etc push the timing and ignition map via the computer that controls these in modern cars to extract the extra power from the fact that per litre 99 octane fuel contains more than 95.