Vpower vs regular

Sneaky Peaky · 17 Oct 2008 at 12:29

Where's all the usual posts about added detergents etc in Vpower helping the engine run better ?

Prophet · 17 Oct 2008 at 13:03

Barry Smalley said:
Where's the higher CR coming from? A head skim?

Again, jumping to conclusions!

I said "higher octane fuel has the ability to to run a higher compression ratio."

Where did I say it related to my car? I was just pointing out a plus side to super unleaded. Surely you know turbo's generally bebefit from a lower CR?

Barry Smalley said:
What detects the knock then? How does the ECU know when to retard?

I have a knock sensor. I was commenting on your assumption that I 'had' to have one like 'all' other UK cars do.

BigT · 17 Oct 2008 at 13:52

I'm confused. If all UK cars are designed to run on UL, how come my CL500, Boxster and TT all state in the manual that SUL should be used and UL only if absoloutely necessary? In fact the Audi manual even says something along the lines of 'I will see reduced power on the lower grade fuel'

Prophet · 17 Oct 2008 at 13:55

BigT said:
I'm confused. If all UK cars are designed to run on UL, how come my CL500, Boxster and TT all state in the manual that SUL should be used and UL only if absoloutely necessary? In fact the Audi manual even says something along the lines of 'I will see reduced power on the lower grade fuel'

Because he was wrong

GeX · 17 Oct 2008 at 13:55

Because all standard UK cars are not designed to run on 95 RON fuel, Barry Smalley and numnutz are both chatting crap.

Jez · 17 Oct 2008 at 13:59

BigT, the M113's definitely do not require SUL, they are very lazy longevity tuned engines designed to run on all types of low grade fuel :confused:

Dogbreath · 17 Oct 2008 at 16:49

Orange Peel said:
Surely you know turbo's generally bebefit from a lower CR?

They don't benefit from it at all. It gives sluggish off boost response and impairs fuel economy. Low CR is simply a compromise to prevent detonation when running lots of boost or with high intake temperatures.

Prophet · 17 Oct 2008 at 16:57

Dogbreath said:
They don't benefit from it at all. It gives sluggish off boost response and impairs fuel economy. Low CR is simply a compromise to prevent detonation when running lots of boost or with high intake temperatures.

Ermm yes they do. You're just looking at the negatives of a pooly spec'd setup and not the positives of a decent setup.

I run slightly lower compression than standard, boost comes in nice and low so off boost sluggishness is minimal and don't suffer from high intake temps. If I ran standard compression I'd have to lower boost which would reduce power.

MrM · 17 Oct 2008 at 20:14

For what it's worth, if I put regular 95 RON in my S2000 the fuel efficiency drops massivley. On V-Power or Tesco high octane stuff I can achieve between 23 and 32mpg depending on driving style, with 95 I struggle to get 18mpg on a tank even when driving conservatively. It seems more sluggish but not sure if thats more psychological, but without any kind of formal test I guess its hard to quantify.