Shell V-Power unleaded price premium over standard
Discussion
DoubleD said:
If you cant feel the difference then get the cheap stuff
If you can feel the difference then get the expensive stuff
Nothing more to it than that
This exactly.If you can feel the difference then get the expensive stuff
Nothing more to it than that
Nothing complicated at all. I get this is an enthusiasts site but quite why people like C70R etc are ridiculed for an opinion is beyond me.
If it works for you, great. If not, save your money.
SOL111 said:
Nothing complicated at all. I get this is an enthusiasts site but quite why people like C70R etc are ridiculed for an opinion is beyond me.
He is not being ridiculed, he is being argued with because he is saying that people are doing mental gymnastics trying to convince themselves it makes a difference. That simply isn't true and comes across as ignorant and rude with it. Not a great combination.
CS Garth said:
If you can’t tell the difference then either the car or driver is not optimised for the fuel.
I’ve had number of performance vehicles, both petrol and NA, and when pressing on the difference is obvious. Cleaner, more linear pick up being a key characteristic.
Exactly. I’ve had number of performance vehicles, both petrol and NA, and when pressing on the difference is obvious. Cleaner, more linear pick up being a key characteristic.
Also, your brain adapts pretty quickly to changes, especially small changes.
The time I really notice a difference is when my wife has once again filled up with 95 ron on the quiet.
A few times I have had to wrangle the truth out of her that she has put 95 in again. I can tell immediately when she has.
Also, I don't get C70r's argument, as he goes on to say he uses Super Unleaded as his car is set up for it.
Whack a tank of 95 in, your car is set up for 95 as well, if you don't think there is a difference why bother with Super?
C70R said:
A good friend who worked in calibration for a major manufacturer talked me through this process, and explained how these engines were built with maps to drive just fine and see out their warranty on the cheapest, crappiest fuel available.
What modern engines are actually able to do is retard timing very quickly and very precisely when they detect knock, on a cylinder-by-cylinder basis - it’s definitely not the case that they’re set up to run on TVO.If a modern engine / ecu is calibrated for 95 fuel, then it won't advance the ignition to take advantage of higher RON fuel. Manufacturers only have an interest in making their engine work as efficiently as possible for the type of fuel being calibrated, there won't be anything "spare". It will obviously retard in response to a lower spec of fuel... I had to use 91RON for a journey in 45 degree heat once, interesting experience. Many cars are calibrated to 98 though, so I'd want to be using super / v power / momentum every time.
NomduJour said:
xjay1337 said:
As I said most cars don't actually know what "octane" of fuel is on board.
They do - the ECU is constantly altering ignition and cylinder pressure/load from its monitoring of knock levels.Not measuring fuel "octane" levels.........
If a car is factory tuned and optimised for 95 Octane and you run 98 octane you will get no benefit from knock resistance.
xjay1337 said:
They are detecting knock
Not measuring fuel "octane" levels.........
... less knock, higher octane. Semantics.Not measuring fuel "octane" levels.........
xjay1337 said:
If a car is factory tuned and optimised for 95 Octane and you run 98 octane you will get no benefit from knock resistance.
How many new cars don't have some provision for advance beyond 95 RON knock levels? (I don't know the answer to that, but I'd wager it's very few).NomduJour said:
xjay1337 said:
They are detecting knock
Not measuring fuel "octane" levels.........
... less knock, higher octane. Semantics.Not measuring fuel "octane" levels.........
xjay1337 said:
If a car is factory tuned and optimised for 95 Octane and you run 98 octane you will get no benefit from knock resistance.
How many new cars don't have some provision for advance beyond 95 RON knock levels? (I don't know the answer to that, but I'd wager it's very few).If the engine timing advance is only set to XX degrees from factory and this is set to what is safe for 95 octane then you get no benefits!
The engine doesn't know what fuel it is running on..............
CS Garth said:
If you can’t tell the difference then either the car or driver is not optimised for the fuel.
I’ve had number of performance vehicles, both petrol and NA, and when pressing on the difference is obvious. Cleaner, more linear pick up being a key characteristic.
Absolutely. I took my 2003 Mini Cooper S out for a drive today with Shell V-Power (99 RON) and on full throttle the difference between this fuel and BP Ultimate (97 RON) is totally obvious. This is in a car with an unmodified engine. I unintentionally met the rev limiter for the first time in many years and the engine didn't sound like it was going to explode either.I’ve had number of performance vehicles, both petrol and NA, and when pressing on the difference is obvious. Cleaner, more linear pick up being a key characteristic.
DJP said:
Grayedout said:
People need to realise that the Octane increase in higher specification fuels is only a part of their differences.
Yes the higher octane will allow some cars to run at a more advanced ignition timing which can result in more power but EVERY car will benefit from the clean up and keep clean performance as well as improved atomisation and burning which will lead to the improved fuel economy that many people in this thread have already experienced.
Allegedly...Yes the higher octane will allow some cars to run at a more advanced ignition timing which can result in more power but EVERY car will benefit from the clean up and keep clean performance as well as improved atomisation and burning which will lead to the improved fuel economy that many people in this thread have already experienced.
https://www.cectests.org/about-cec.asp
The problem is there is no standard for fuel performance and so there is nothing to quote that the general public would understand!
xjay1337 said:
It's not semantics. It's a fundamental lack of understanding of how the engine works.
If the engine timing advance is only set to XX degrees from factory and this is set to what is safe for 95 octane then you get no benefits!
The engine doesn't know what fuel it is running on..............
You don’t understand this, clearly. Show me load/timing tables from a current factory map that doesn’t have the provision to put in advance beyond what 95 RON fuel can take. If the engine timing advance is only set to XX degrees from factory and this is set to what is safe for 95 octane then you get no benefits!
The engine doesn't know what fuel it is running on..............
NomduJour said:
xjay1337 said:
It's not semantics. It's a fundamental lack of understanding of how the engine works.
If the engine timing advance is only set to XX degrees from factory and this is set to what is safe for 95 octane then you get no benefits!
The engine doesn't know what fuel it is running on..............
You don’t understand this, clearly. Show me load/timing tables from a current factory map that doesn’t have the provision to put in advance beyond what 95 RON fuel can take. If the engine timing advance is only set to XX degrees from factory and this is set to what is safe for 95 octane then you get no benefits!
The engine doesn't know what fuel it is running on..............
Let's say a cars factory optimised tune is ran on 98 but can take 95 octane (as is common on many cars)
If someone puts in 95 then it will detect knock and pull timing until there is no knock. The car doesn't know it is on 95 fuel, but retards timing.
The engine doesn't have a sensor to say there is 95 octane on there. The knock sensor with the factory tune that has the ability to retard the timing to a certain degree. While you can't detect what type of fuel is in the factory calibration may know that with 95 fuel you can run say 22 degrees of advance but with 98 you can 26 degrees (an example).
So it will try to run 26 degreess but if it sees knock it will fall back to 22. This isn't because the car knows what octane is in the tank, it is just reacting to knock.
But in the case of one of the previous posters 2.0 Hyundai Coupe there is NO MAP FOR ADVANCE BASED ON ## OCTANE.
And even on many more modern cars , this doesn't exist
It may in the very, very latest OEM cars from but, it is not a common factory feature
Many AFTERMARKET ECU's in conjunction with AN AFTERMARKET FLEX FUEL SENSOR (which measures ethanol content, not octane, COS YOU CAN'T MEASURE OCTANE) can have a variety of maps depending on if you're running e85 right through to plain straight 95 unleaded.
Why do you think if your car gets mapped on 99 fuel it's vital you continue to use it?
Otherwise the ECU would just read a second table based on this magical octane measurement.
Edited by xjay1337 on Sunday 21st July 09:54
gizlaroc said:
The time I really notice a difference is when my wife has once again filled up with 95 ron on the quiet.
A few times I have had to wrangle the truth out of her that she has put 95 in again. I can tell immediately when she has.
Seriously? A few times I have had to wrangle the truth out of her that she has put 95 in again. I can tell immediately when she has.
How do you 'wrangle' the truth out of her exactly?
Do you have to sit her in a dark room with a spotlight on her face for hours in order to break her?
And we're the odd one's
Sorry, just taking the mick as the prospect of you driving your car, the epiphany and subsequent grilling of your wife cracked me up.
Edited by SOL111 on Sunday 21st July 10:10
SOL111 said:
Seriously?
How do you 'wrangle' the truth out of her exactly?
Do you have to sit her in a dark room with a spotlight on her face for hours in order to break her?
And we're the odd one's
Sorry, just taking the mick as the prospect of you driving your car, the epiphany and subsequent grilling of your wife cracked me up.
I wangle it out of her because she swears blind she has put 98 in, she manages to keep a straight face for a good 10 minutes or so before laughing at me. How do you 'wrangle' the truth out of her exactly?
Do you have to sit her in a dark room with a spotlight on her face for hours in order to break her?
And we're the odd one's
Sorry, just taking the mick as the prospect of you driving your car, the epiphany and subsequent grilling of your wife cracked me up.
She also thinks I am a t
t. She only sees that 98 is 5p a litre more, misses that we get almost 10% more in mpg and the car feels nicer to drive too.
I've more or less run NA petrols over the past 18 years.
I currently have an X308 XJR for my daily car and 156 v6 Alfa that I use at weekends.
I'm not sure I can tell if the XJR is any quicker but the Alfa is noticeably more perky with anything better than 95. It feels much more 'bogged down' when using 95. Plus I've noticed in many cars I've owned over the years, an improvement in MPG; that alone makes it worth paying more for the better stuff.
It definitely makes a difference with some cars. MPG and/or power.
I currently have an X308 XJR for my daily car and 156 v6 Alfa that I use at weekends.
I'm not sure I can tell if the XJR is any quicker but the Alfa is noticeably more perky with anything better than 95. It feels much more 'bogged down' when using 95. Plus I've noticed in many cars I've owned over the years, an improvement in MPG; that alone makes it worth paying more for the better stuff.
It definitely makes a difference with some cars. MPG and/or power.
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