Shell V-Power Nitro+
Discussion
At the risk of being shot down in flames...
My 997S.2 runs better on Tesco 99-RON than it does on Shell.
1) Far better cold start. (Smooth and even on Tesco, lumpy on Shell).
2) Better part-throttle response. (Immediate and clean on Tesco, occasional tiny lag on Shell).
3) No difference in full-throttle mid-range torque. (As you'd expect with the same octane rating).
3) Noticeably better performance above 6000rpm. (Revs very cleanly to the limiter on Tesco. Sounds/feels like it's going over-advanced on Shell).
My working theory for the differences is that it's down to different burn rates between the 2 fuels. Tiny, tiny differences in burn rate make a big difference in how the engine responds - particularly at highish rpm. For example - from ignition to opening of the exhaust valve at 6000 rpm takes approx. 0.006-0.007 of a second. From ignition to the piston going over TDC only takes about 0.001 of a second. As you'll interpret from these miniscule times, the rate of burn of 2 fuels only has to differ by fractions of a millisecond to play havoc with the accuracy of your ignition maps. So maybe it's not all that surprising we feel and hear differences between fuels. Perhaps the bigger surprise is the differences aren't a lot more pronounced.
My 997S.2 runs better on Tesco 99-RON than it does on Shell.
1) Far better cold start. (Smooth and even on Tesco, lumpy on Shell).
2) Better part-throttle response. (Immediate and clean on Tesco, occasional tiny lag on Shell).
3) No difference in full-throttle mid-range torque. (As you'd expect with the same octane rating).
3) Noticeably better performance above 6000rpm. (Revs very cleanly to the limiter on Tesco. Sounds/feels like it's going over-advanced on Shell).
My working theory for the differences is that it's down to different burn rates between the 2 fuels. Tiny, tiny differences in burn rate make a big difference in how the engine responds - particularly at highish rpm. For example - from ignition to opening of the exhaust valve at 6000 rpm takes approx. 0.006-0.007 of a second. From ignition to the piston going over TDC only takes about 0.001 of a second. As you'll interpret from these miniscule times, the rate of burn of 2 fuels only has to differ by fractions of a millisecond to play havoc with the accuracy of your ignition maps. So maybe it's not all that surprising we feel and hear differences between fuels. Perhaps the bigger surprise is the differences aren't a lot more pronounced.
Ian_UK1 said:
At the risk of being shot down in flames...
My 997S.2 runs better on Tesco 99-RON than it does on Shell.
1) Far better cold start. (Smooth and even on Tesco, lumpy on Shell).
2) Better part-throttle response. (Immediate and clean on Tesco, occasional tiny lag on Shell).
3) No difference in full-throttle mid-range torque. (As you'd expect with the same octane rating).
3) Noticeably better performance above 6000rpm. (Revs very cleanly to the limiter on Tesco. Sounds/feels like it's going over-advanced on Shell).
My working theory for the differences is that it's down to different burn rates between the 2 fuels. Tiny, tiny differences in burn rate make a big difference in how the engine responds - particularly at highish rpm. For example - from ignition to opening of the exhaust valve at 6000 rpm takes approx. 0.006-0.007 of a second. From ignition to the piston going over TDC only takes about 0.001 of a second. As you'll interpret from these miniscule times, the rate of burn of 2 fuels only has to differ by fractions of a millisecond to play havoc with the accuracy of your ignition maps. So maybe it's not all that surprising we feel and hear differences between fuels. Perhaps the bigger surprise is the differences aren't a lot more pronounced.
but could this be shell is 98 and tesco 99?My 997S.2 runs better on Tesco 99-RON than it does on Shell.
1) Far better cold start. (Smooth and even on Tesco, lumpy on Shell).
2) Better part-throttle response. (Immediate and clean on Tesco, occasional tiny lag on Shell).
3) No difference in full-throttle mid-range torque. (As you'd expect with the same octane rating).
3) Noticeably better performance above 6000rpm. (Revs very cleanly to the limiter on Tesco. Sounds/feels like it's going over-advanced on Shell).
My working theory for the differences is that it's down to different burn rates between the 2 fuels. Tiny, tiny differences in burn rate make a big difference in how the engine responds - particularly at highish rpm. For example - from ignition to opening of the exhaust valve at 6000 rpm takes approx. 0.006-0.007 of a second. From ignition to the piston going over TDC only takes about 0.001 of a second. As you'll interpret from these miniscule times, the rate of burn of 2 fuels only has to differ by fractions of a millisecond to play havoc with the accuracy of your ignition maps. So maybe it's not all that surprising we feel and hear differences between fuels. Perhaps the bigger surprise is the differences aren't a lot more pronounced.
f1ashgordon said:
Mine (997.2S) runs better on tesco momentum (3% cash back with santander 123 credit card FYI so it's 127p) as opposed to nitro. no idea why is it 99 vs 98 as suggested?
No they are both 99. Optimax was 98 but ever since the re branding to V-Power Shell have claimed 99 ron. itsybitsy said:
how is your car now after its problems?did they all get sorted?
Car's great thank you, no problems since and 10k in 13 months, none of it commuting or work related, just lots of Brecon Beacons, Black Mountain et al driving; think I had probably the best two hours of my life driving back for Mother's Day!itsybitsy said:
Ian_UK1 said:
At the risk of being shot down in flames...
My 997S.2 runs better on Tesco 99-RON than it does on Shell.
1) Far better cold start. (Smooth and even on Tesco, lumpy on Shell).
2) Better part-throttle response. (Immediate and clean on Tesco, occasional tiny lag on Shell).
3) No difference in full-throttle mid-range torque. (As you'd expect with the same octane rating).
3) Noticeably better performance above 6000rpm. (Revs very cleanly to the limiter on Tesco. Sounds/feels like it's going over-advanced on Shell).
My working theory for the differences is that it's down to different burn rates between the 2 fuels. Tiny, tiny differences in burn rate make a big difference in how the engine responds - particularly at highish rpm. For example - from ignition to opening of the exhaust valve at 6000 rpm takes approx. 0.006-0.007 of a second. From ignition to the piston going over TDC only takes about 0.001 of a second. As you'll interpret from these miniscule times, the rate of burn of 2 fuels only has to differ by fractions of a millisecond to play havoc with the accuracy of your ignition maps. So maybe it's not all that surprising we feel and hear differences between fuels. Perhaps the bigger surprise is the differences aren't a lot more pronounced.
but could this be shell is 98 and tesco 99?My 997S.2 runs better on Tesco 99-RON than it does on Shell.
1) Far better cold start. (Smooth and even on Tesco, lumpy on Shell).
2) Better part-throttle response. (Immediate and clean on Tesco, occasional tiny lag on Shell).
3) No difference in full-throttle mid-range torque. (As you'd expect with the same octane rating).
3) Noticeably better performance above 6000rpm. (Revs very cleanly to the limiter on Tesco. Sounds/feels like it's going over-advanced on Shell).
My working theory for the differences is that it's down to different burn rates between the 2 fuels. Tiny, tiny differences in burn rate make a big difference in how the engine responds - particularly at highish rpm. For example - from ignition to opening of the exhaust valve at 6000 rpm takes approx. 0.006-0.007 of a second. From ignition to the piston going over TDC only takes about 0.001 of a second. As you'll interpret from these miniscule times, the rate of burn of 2 fuels only has to differ by fractions of a millisecond to play havoc with the accuracy of your ignition maps. So maybe it's not all that surprising we feel and hear differences between fuels. Perhaps the bigger surprise is the differences aren't a lot more pronounced.
fullleather said:
Tescos momentum 99ron, you cant go wrong with the stuff £1.31 a litre, 9000rpm never felt so good, my f20c engine adores it, no daft friction/fiction malarkey....nitro+ I ask? the men in white coats must be having a right laugh amongst themselves...
I ran an S2000 for 18k miles a few years ago, most of which was an identical commute out of London up and down the M3 in early mornings/afternoons out of much traffic ( yes I know, not exactly the ultimate commuter weapon 
) . Out of 95, 97 and 99 RON fuels:1) 97 gave me best mpg by a margin of about 1.5mpg (based on fill up logs I did) and was the cheapest fuel to use in terms of pence per mile travelled, and subjectively (I.e bum accelerometer) felt like it gave me better mid range than the others
2) 99 gave me worse fuel consumption than 97 but about the same as 95, but subjectively the best top end of them all
3) 95 was the worst on all accounts, engine really did not seem to like it
if you see inside the fuel flap, there is a sticker showing 98 as recommended by Honda (no mention of these friction/fiction extras I might add) This Shell nitro b
ks is just marketed in such a way as to make the user feel they are 'buying into the Ferrari brand) 'if its used/developed/ by Ferrari it must be the best for my car'
ks is just marketed in such a way as to make the user feel they are 'buying into the Ferrari brand) 'if its used/developed/ by Ferrari it must be the best for my car' Mario149 said:
I ran an S2000 for 18k miles a few years ago, most of which was an identical commute out of London up and down the M3 in early mornings/afternoons out of much traffic ( yes I know, not exactly the ultimate commuter weapon ) . Out of 95, 97 and 99 RON fuels:
1) 97 gave me best mpg by a margin of about 1.5mpg (based on fill up logs I did) and was the cheapest fuel to use in terms of pence per mile travelled, and subjectively (I.e bum accelerometer) felt like it gave me better mid range than the others
2) 99 gave me worse fuel consumption than 97 but about the same as 95, but subjectively the best top end of them all
3) 95 was the worst on all accounts, engine really did not seem to like it
Not surprising though if the S2000 doesn't have a knock sensor - does it? If not, all fuels that have a different RON to which the ECU is mapped will be sub optimal for performance and mpg, including the higher RONs. The more advanced additives in the VPower should be what is making the difference vs stock 95 RON.) . Out of 95, 97 and 99 RON fuels:1) 97 gave me best mpg by a margin of about 1.5mpg (based on fill up logs I did) and was the cheapest fuel to use in terms of pence per mile travelled, and subjectively (I.e bum accelerometer) felt like it gave me better mid range than the others
2) 99 gave me worse fuel consumption than 97 but about the same as 95, but subjectively the best top end of them all
3) 95 was the worst on all accounts, engine really did not seem to like it
on that note, I also found that the alleged 28mpg combined value for the S2000 was a complete fiction itsybitsy said:
but could this be shell is 98 and tesco 99?
I don't think that's the case - they're both listed as 99-RON. I'm also not aware of burn rate being proportional to octane rating. As far as I can ascertain, the two are independent with burn rate being determined more by the overall formulation of the fuel.Gassing Station | Porsche General | Top of Page | What's New | My Stuff