Discussion
I know this topic has been done to death, but with E10 now mainstream, I thought it was worth revisiting 
I’ve had cars remapped to run on 99 RON with fantastic results, I’ve also had cars mapped from the factory to run on 95 RON, that drove significantly better when running on 99 RON.
Given that Porsches are mapped to take advantage of 98 Octane, it’s ironic then that I’ve done over 100,000 miles across numerous models, and I’ve never been able to tell the difference between regular or V-power fuel.
That’s everything from Caymans to Macans to Panamera Turbos, as such, I just stick with the regular stuff.
If I’m doing a track day I’ll use V Power as a matter of course, but even if I use one or two tanks before the track day, then four tanks on the track day and a tank or two back home, I still can’t tell the difference.
So I wonder, am I the only one?
I’ve had cars remapped to run on 99 RON with fantastic results, I’ve also had cars mapped from the factory to run on 95 RON, that drove significantly better when running on 99 RON.
Given that Porsches are mapped to take advantage of 98 Octane, it’s ironic then that I’ve done over 100,000 miles across numerous models, and I’ve never been able to tell the difference between regular or V-power fuel.
That’s everything from Caymans to Macans to Panamera Turbos, as such, I just stick with the regular stuff.
If I’m doing a track day I’ll use V Power as a matter of course, but even if I use one or two tanks before the track day, then four tanks on the track day and a tank or two back home, I still can’t tell the difference.
So I wonder, am I the only one?
Grantstown said:
Rightly or wrongly I use V-Power to try and avoid carbon build up. My 911 is a keeper so I want to look after it.
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.Mr Spoon said:
I hope you guys have an understanding of what octane does and why you would use it. It's not for more power.
An engine operates at its most efficient on the edge of detonation (knock). The higher the octane, the higher the fuel's resistance to knock, which means efficiency can rise slightly, by for (one) example advancing the ignition a few more degrees. Higher octane can permit higher compression ratios, which again increase efficiency (up to a point).Lexington59 said:
Grantstown said:
Rightly or wrongly I use V-Power to try and avoid carbon build up. My 911 is a keeper so I want to look after it.
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.I hear Taffy as well with the ethanol issue. I’m not sure if the V Power is 0% ethanol in my area (Cheshire).
I use Tesco Momentum wherever possible now. Much cheaper than the others too.
My 993 revs to the redline with noticeably more enthusiasm than V-power which I religiously used beforehand. Also I filled up my Ferrari 308 with Momentum for the first time last Autumn and the difference was amazing. Again revving to the redline with real gusto. Even my 16 year old niece noticed the difference!
Haven't tried it in my 991.2 GT3 yet but I can't see that engine needing help with revs!
My 993 revs to the redline with noticeably more enthusiasm than V-power which I religiously used beforehand. Also I filled up my Ferrari 308 with Momentum for the first time last Autumn and the difference was amazing. Again revving to the redline with real gusto. Even my 16 year old niece noticed the difference!
Haven't tried it in my 991.2 GT3 yet but I can't see that engine needing help with revs!
browngt3 said:
I use Tesco Momentum wherever possible now. Much cheaper than the others too.
My 993 revs to the redline with noticeably more enthusiasm than V-power which I religiously used beforehand. Also I filled up my Ferrari 308 with Momentum for the first time last Autumn and the difference was amazing. Again revving to the redline with real gusto. Even my 16 year old niece noticed the difference!
Haven't tried it in my 991.2 GT3 yet but I can't see that engine needing help with revs!
you might think this, but it doesn't happen like you describe. Its the placebo effect. My 993 revs to the redline with noticeably more enthusiasm than V-power which I religiously used beforehand. Also I filled up my Ferrari 308 with Momentum for the first time last Autumn and the difference was amazing. Again revving to the redline with real gusto. Even my 16 year old niece noticed the difference!
Haven't tried it in my 991.2 GT3 yet but I can't see that engine needing help with revs!
Mr Spoon said:
I hope you guys have an understanding of what octane does and why you would use it. It's not for more power.
I understood that the car was able to change the spark timing to allow ignition at a higher piston compression point and that this leads to increased power. Higher octane fuels allow higher compression ratios in cars to start with, meaning more power. Of course the compression ratio is fixed, but the timing can be changed.I noticed 5% better mpg in my 2012 TTS. I'd been using standard for a while then switched to VPower.
In my 981 I'd always used VPower for 40k miles but switched to standard since the "fuel shortage" as the possibly better economy doesn't now beat the 15p price difference.
I've noticed no drop in performance. Too early for long term mpg comparison. On VPower I got 36mpg over 9999 miles.
I will put in a tank of VPower from time to time.
Don't touch Tesco since warned off it by a BMW technician. It knackered my wife's EGR valve.
In my 981 I'd always used VPower for 40k miles but switched to standard since the "fuel shortage" as the possibly better economy doesn't now beat the 15p price difference.
I've noticed no drop in performance. Too early for long term mpg comparison. On VPower I got 36mpg over 9999 miles.
I will put in a tank of VPower from time to time.
Don't touch Tesco since warned off it by a BMW technician. It knackered my wife's EGR valve.
DJMC said:
Don't touch Tesco since warned off it by a BMW technician. It knackered my wife's EGR valve.
and how exactly does the BMW grease monkey know the EGR valve failure was caused by fuel and specifically sold by Tesco? Take a trip to a local refinery or storage terminal. Count how many petrol tanks are there. Now work out how many companies there are, then do the math.
PS i run a fuel company if you want my "credentials"
Grease monkey had 17 years experience with Porsche; Lamborghini; RR; and was peering into the engine bay, on my drive. Looking at the blocked EGR he asked "have you been using supermarket fuel?"
"Yes, Tesco."
Ah, that'll be it then."
He proceeded to explain why, in detail.
I knew he was a motor technician as he was wearing a BMW technician's uniform, and had a BMW emergency services van.
Other's here have no proven credentials.
After four years of avoiding Tesco we've had no further issues.
"Yes, Tesco."
Ah, that'll be it then."
He proceeded to explain why, in detail.
I knew he was a motor technician as he was wearing a BMW technician's uniform, and had a BMW emergency services van.
Other's here have no proven credentials.
After four years of avoiding Tesco we've had no further issues.
DJMC said:
Grease monkey had 17 years experience with Porsche; Lamborghini; RR; and was peering into the engine bay, on my drive. Looking at the blocked EGR he asked "have you been using supermarket fuel?"
"Yes, Tesco."
Ah, that'll be it then."
He proceeded to explain why, in detail.
I knew he was a motor technician as he was wearing a BMW technician's uniform, and had a BMW emergency services van.
Other's here have no proven credentials.
After four years of avoiding Tesco we've had no further issues.
I don't care how long this person has been in the industry or who he has worked for. This is complete BS. "Yes, Tesco."
Ah, that'll be it then."
He proceeded to explain why, in detail.
I knew he was a motor technician as he was wearing a BMW technician's uniform, and had a BMW emergency services van.
Other's here have no proven credentials.
After four years of avoiding Tesco we've had no further issues.
Do you not realise that the majority of this rubbish about fuel is exactly that rubbish.
So one of the UKs largest forecourt network and largest overall domestic volume of fuel all of a sudden is causing egr valves to block. If you believe that then please hand me some cash. I'd like some of what you are so eager to give away. Wow
smudger911 said:
Mr Spoon - As you are in the industry I'd really appreciate some insight. Are we being sold snake oil (excuse the pun) with the more expensive fuels or is the extra cost justified with added detergents etc?
You pay your money and you get what they advertise. The reality is the standard fuel spec in this country far exceeds all manufacturers requirements. This will end up in some know it all pub crap debate, but put it this way, either petrol or diesel, you won't have an issue regardless of the branding of the garage.
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