Anyone dyno’d MY19 Cupra in standard form?

Betts-4

Active Member
Jul 11, 2019
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Some cars dont like some fuels, its that simple. My Cupra doesnt like Morrisons Super, its flat, sounds different and doesnt rev as freely. It comes alive on Momentum.
Maybe I need to take it back having looked on few threads lot recommending Tesco momentum so maybe I’ll give it a go and collect those points :)
 
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Dannnnn

Active Member
Dec 9, 2018
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Some cars dont like some fuels, its that simple. My Cupra doesnt like Morrisons Super, its flat, sounds different and doesnt rev as freely. It comes alive on Momentum.

Agreed.
My 335i hated BP premium (it made it misfire and run rough) but Tesco, Esso or Shell and it was fine.

I've only run the Cupra on Tesco 99 and it's fine.
 

Butty

Active Member
Sep 7, 2018
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Anyone log the mass air load gms/sec during any dyno runs? Am interested to see if the old rule of thumb that 1.25 times gms/sec equals HP
 

GordonMcC

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Feb 8, 2017
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Fifth Gear done a fuel test on Golf Gti Mk6 a few years back. Shwll V POwer and ESSO came out top. BP Ultimate over BP "Standard" made 0.6hp more
I find the 99RON from Tesco to be absolutely fine

 

KXL

KXL
Dec 15, 2016
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London, UK
If I'm not mistaken, Esso/Texaco/BP/Jet's finest are 97 RON, Shell Vpower and Tesco Momentum are both 99RON. Once upon a time BP had 102RON fuel, but they stopped it. It's not uncommon to see supercars, and GTIs, Audi S/RS and BMW M spec cars (not Msport trim) filling at my local tesco, guess they are putting Momentum 99. My personal experience on a non-performance car, Shell Vpower gave me best Mpg, Esso Supreme 97 gave me the smoothest engine having tried all the non-supermarket petrol. Cannot feel any difference in power in any.
 

ChrisM75

Active Member
May 10, 2019
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Most of the supers ive tried make little difference relative to each other really, apart from Morrisons. That may have been because its new (8-9 months) to my local station and hasnt been used much, so is perhaps going stale.

The primary difference is price with Momentum and most supermarket brands being 130.9, whereas the 'premium' brands being between 137.9 and 158.9!
 

ChrisM75

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May 10, 2019
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So are we saying in general mementum and V power are the way to go
Seat say to get max power you need 98 RON fuel, which really only means Momentum and V Power since all the others are 97. How much difference it really makes is uncertain.

Momentum works fine with no problems or rough running, and its cheaper than branded Supers.
 

KXL

KXL
Dec 15, 2016
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London, UK
So are we saying in general mementum and V power are the way to go
Consensus is yes, I saw a video somewhere, where they put Shell Vpower (from the petrol station) into Fernando's Aloso's F1 Ferrarri race car during a test (back then), and he was surprised he didn't feel much (if any) difference, but only when views on telemetry there were some small differences. I don't know what RON is Shell Vpower Race fuel though, maybe 102
 

GordonMcC

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Feb 8, 2017
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Ayrshire, Scotland
Seat say to get max power you need 98 RON fuel, which really only means Momentum and V Power since all the others are 97. How much difference it really makes is uncertain.

Momentum works fine with no problems or rough running, and its cheaper than branded Supers.


Momentum is cheaper than Branded basic fuels never meant the supers!
 

salsajoe

Active Member
Apr 12, 2017
130
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Yorkshire
I have found that V-power leaves virtually no 'soot' at the exhaust tips with Momentum slightly more. Not sure if this means much? Perhaps more complete combustion? Found a lot of regular fuels leave lots of soot so these are the only ones I use these days.
 

ChrisM75

Active Member
May 10, 2019
423
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Momentum is cheaper than Branded basic fuels never meant the supers!
Not quite where I am. Momentum is 131.9, most branded 95RON is 127.9, but still its worth it. V-Power is 139.9, so even if it was slightly better, its not worth over £4 a tank more.
 

GordonMcC

Active Member
Feb 8, 2017
284
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Ayrshire, Scotland
Not quite where I am. Momentum is 131.9, most branded 95RON is 127.9, but still its worth it. V-Power is 139.9, so even if it was slightly better, its not worth over £4 a tank more.

fair enough but obviously prices for fuel vary so much. we have 2 BPs within 2 miles of each other yet one is always dearer by 2-3p
 

LouG

Active Member
Dec 1, 2017
1,319
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Nelson, New Zealand
I
Anyone log the mass air load gms/sec during any dyno runs? Am interested to see if the old rule of thumb that 1.25 times gms/sec equals HP
I've never heard of that. But it doesn't take into account mechanical variables like friction, traction on the rollers, correction factors, etc.
 

ChrisM75

Active Member
May 10, 2019
423
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I

I've never heard of that. But it doesn't take into account mechanical variables like friction, traction on the rollers, correction factors, etc.
A lot of manufacturers figures for power, and performance are just calculations and not really tested. Given that quoted power is at the flywheel anyway they are pretty good at calculating it.
 

Butty

Active Member
Sep 7, 2018
156
46
I

I've never heard of that. But it doesn't take into account mechanical variables like friction, traction on the rollers, correction factors, etc.
Yes it will do as it is the air demand of the engine in response to those forces acting against it.
These differ whether on the road or a dyno, altough dynos try to mimick actual road loadings through their correction factors.
Good dynos operators can simulate road response very well on their rigs and are then able to tune equally well on the dyno or road with good confidence in gms/sec reflecting HP output.
 

LouG

Active Member
Dec 1, 2017
1,319
481
Nelson, New Zealand
Yes it will do as it is the air demand of the engine in response to those forces acting against it.
These differ whether on the road or a dyno, altough dynos try to mimick actual road loadings through their correction factors.
Good dynos operators can simulate road response very well on their rigs and are then able to tune equally well on the dyno or road with good confidence in gms/sec reflecting HP output.
No, it won't. A given engine will only pump such air as its volumetric efficiency will allow. It will not keep pumping more air as load decreases. The rest of its power output is governed by thermal efficiency, and its rev limit.
Increase any/or all three and you increase power. Power for a given mass airflow will vary according to AFR and ignition advance as well.
 

OptimusDecline

Active Member
Feb 24, 2016
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17
Scotland
A lot of manufacturers figures for power, and performance are just calculations and not really tested. Given that quoted power is at the flywheel anyway they are pretty good at calculating it.

Is this right? Surely the manfacturers will test the engines on an engine dyno for the performance logging? Thats why they quote power and torque at flywheel, because they don't measure on a rolling road.
 
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KXL

KXL
Dec 15, 2016
1,581
197
London, UK
I have found that V-power leaves virtually no 'soot' at the exhaust tips with Momentum slightly more. Not sure if this means much? Perhaps more complete combustion? Found a lot of regular fuels leave lots of soot so these are the only ones I use these days.

On GPF fitted petrol cars, it doesn't leave any soot at all..
 

ChrisM75

Active Member
May 10, 2019
423
182
Is this right? Surely the manfacturers will test the engines on an engine dyno for the performance logging? Thats why they quote power and torque at flywheel, because they don't measure on a rolling road.
They do test of course, but every engine is a little different. They know that certain parameters will generate a certain output without needing to test the physical output again.

Sometimes power outputs are pure marketing. My last car was an Astra 1.4T with 150PS. It also came in 125PS, but based on engine data that was nearer 135/8, when tested by an owner it was reported to be 140 which given dyno optimism seems about right. The 150 is more like 160.
 
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