Super unleaded
Discussion
Posted here as this is a general Speed 6 question/observation.
99% of the time I have had my car it has been filled with Shell Optimax, or whatever it's been called in the past 10 years. This was purely based on the information found on here and I've never had a reason to switch. However last week I got a low fuel warning when only a couple of miles from a Tesco station so stopped for a quick splash and dash. Looking at how cheap it was though I thought what the hell fill her up. Next day start up and straight away it felt smoother and after warming up the pops bangs and explosions were doubled (what a great smilie, this is exactly what each exhaust sounds like).
So was wondering what others had experienced. I am going for a retune in the new year, but now wondering whether to have it mapped purely for 97 or 99 octane? Obviously will take advice from whoever does the work but interested in others thoughts.
Bad experience with standard octane so will never use that again btw.
99% of the time I have had my car it has been filled with Shell Optimax, or whatever it's been called in the past 10 years. This was purely based on the information found on here and I've never had a reason to switch. However last week I got a low fuel warning when only a couple of miles from a Tesco station so stopped for a quick splash and dash. Looking at how cheap it was though I thought what the hell fill her up. Next day start up and straight away it felt smoother and after warming up the pops bangs and explosions were doubled (what a great smilie, this is exactly what each exhaust sounds like).
So was wondering what others had experienced. I am going for a retune in the new year, but now wondering whether to have it mapped purely for 97 or 99 octane? Obviously will take advice from whoever does the work but interested in others thoughts.
Bad experience with standard octane so will never use that again btw.
Always gone with Shell V-Power or what they call it... as its recommended by Dom at Power and the engine likes it.
However a few years back in my Dads Cerbera was in the same situation and filled with Tesco Super unleaded and thought exactly the same thing. The car did feel even sharper?? I know some people have said Tesco Octane was 99 and I now believe shell have gone from 98 to 99 so lets wait and see. People on here often say Tesco fuel can cause problems?
I'll be sticking with Shell as its always nice to get £5 off every so often
However a few years back in my Dads Cerbera was in the same situation and filled with Tesco Super unleaded and thought exactly the same thing. The car did feel even sharper?? I know some people have said Tesco Octane was 99 and I now believe shell have gone from 98 to 99 so lets wait and see. People on here often say Tesco fuel can cause problems?
I'll be sticking with Shell as its always nice to get £5 off every so often
To claim an Octane rating (or research octane number RON)in the UK the fuel must pass the relevant BS EN standards. Therefore, in terms of anti-knock concerns, if the fuel has an Octane rating of 98 or above it will be perfect for any high performance engines. Beyond the RON rating the only differences are the allowable additives that might be in the fuel. Then it becomes a matter or whether you believe the marketing hype or not because there is no requirement for a manufacturer to prove their claims (cleaner burning, will help clean injectors, etc., etc.).
I have run a range of high performance cars over recent years all requiring 98 Octane fuel. I have used Shell V-Power, BP Super unleaded and Tesco 99 (which I think is from Esso??)and I can honestly say I have never felt any difference in any car.
I have run a range of high performance cars over recent years all requiring 98 Octane fuel. I have used Shell V-Power, BP Super unleaded and Tesco 99 (which I think is from Esso??)and I can honestly say I have never felt any difference in any car.
Could it be down to how the car was mapped??
I did the same sort of thing recently. The T350 lives on BP super but I had to stick normal unleaded into the T350 as I was at the 4 litre warning... and it honestly felt a lot smoother to drive and reduction in some hesitations.
I was wondering if the car was mapped to run on normal unleaded (is that possible?) would putting super in it cause it to be a little temperamental?
I did the same sort of thing recently. The T350 lives on BP super but I had to stick normal unleaded into the T350 as I was at the 4 litre warning... and it honestly felt a lot smoother to drive and reduction in some hesitations.
I was wondering if the car was mapped to run on normal unleaded (is that possible?) would putting super in it cause it to be a little temperamental?
Modern fuel injected engines are actually very tolerant of a wide range of RON fuels. The addition of octanes in a fuel actually make it harder to combust - therefore reducing the risk of pre-detonation (knocking). However, when a high octane fuel does combust it creates a really efficient burn and therefore gives a bigger bang!
I am no expert regarding ECU mapping but I guess it is possible to have a map that retards the ignition and reduces the risk of knocking but I can't see how this would make the engine performance seem smoother. However, we are talking about TVRs so anything is possible!
I am no expert regarding ECU mapping but I guess it is possible to have a map that retards the ignition and reduces the risk of knocking but I can't see how this would make the engine performance seem smoother. However, we are talking about TVRs so anything is possible!
Some interesting replies thanks. I will be sticking to Shell as their fuel has kept my engine clean for the last 10 years a bit of a no brainer, especially if as Incognegro says they may be up to 99 octane now it will mean I have an extra option for Tescos special pops and bangs!
I am deciding whether to refit some sports cats for longer journeys next year but need to balance that with shorter trip aural pleasures , but will have the remap done over the winter anyway to experience the difference.
I am deciding whether to refit some sports cats for longer journeys next year but need to balance that with shorter trip aural pleasures , but will have the remap done over the winter anyway to experience the difference.
monty quick said:
Modern fuel injected engines are actually very tolerant of a wide range of RON fuels. The addition of octanes in a fuel actually make it harder to combust - therefore reducing the risk of pre-detonation (knocking)
They're tolerant as they use knock sensors. Antique MBE doesn't....The problem is the load of the engine, for normal use in GB 95 oct should be o.k.
But on high loads(=high temp in combustion chamber, = high pressure in combustion chamber)
the engine can start high rev pinking.
This is mostly due to high revs not to hear by human ears, therefore on modern engines
knock sensors are installed and the ignition will be adjusted to lower temps and to take load from engine.
In Germany on Autobahn when you drive 120 mls/h you need approx 130-150 hp.
Over in your country when you drive only moderate 60 mls you only need 40-55 hp, so no consistant high temp occured and when engine is not adjusted for max output 95 oct can be sufficent.
But the risk is always present, and when engine goes "Pop" you get a big hole in your wallet
(and Dom gets a smile in his face)
Uwe
But on high loads(=high temp in combustion chamber, = high pressure in combustion chamber)
the engine can start high rev pinking.
This is mostly due to high revs not to hear by human ears, therefore on modern engines
knock sensors are installed and the ignition will be adjusted to lower temps and to take load from engine.
In Germany on Autobahn when you drive 120 mls/h you need approx 130-150 hp.
Over in your country when you drive only moderate 60 mls you only need 40-55 hp, so no consistant high temp occured and when engine is not adjusted for max output 95 oct can be sufficent.
But the risk is always present, and when engine goes "Pop" you get a big hole in your wallet
(and Dom gets a smile in his face)
Uwe
Tuscanuwe said:
The problem is the load of the engine, for normal use in GB 95 oct should be o.k.
But on high loads(=high temp in combustion chamber, = high pressure in combustion chamber)
the engine can start high rev pinking.
This is mostly due to high revs not to hear by human ears, therefore on modern engines
knock sensors are installed and the ignition will be adjusted to lower temps and to take load from engine.
In Germany on Autobahn when you drive 120 mls/h you need approx 130-150 hp.
Over in your country when you drive only moderate 60 mls you only need 40-55 hp, so no consistant high temp occured and when engine is not adjusted for max output 95 oct can be sufficent.
But the risk is always present, and when engine goes "Pop" you get a big hole in your wallet
(and Dom gets a smile in his face)
Uwe
The handbook page shown above says for track use it should be 98 RON - and I guess the autobahn falls into that category with sustained high speeds. If you do that on public roads in the UK you will soon be facing a big fine and a driving ban ...But on high loads(=high temp in combustion chamber, = high pressure in combustion chamber)
the engine can start high rev pinking.
This is mostly due to high revs not to hear by human ears, therefore on modern engines
knock sensors are installed and the ignition will be adjusted to lower temps and to take load from engine.
In Germany on Autobahn when you drive 120 mls/h you need approx 130-150 hp.
Over in your country when you drive only moderate 60 mls you only need 40-55 hp, so no consistant high temp occured and when engine is not adjusted for max output 95 oct can be sufficent.
But the risk is always present, and when engine goes "Pop" you get a big hole in your wallet
(and Dom gets a smile in his face)
Uwe
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