TBH I haven't noticed any significant difference in mpg but as a follower of HJ who extols the benefits of V Power every single week I have used it regularly.

I keep detailed records - manually and Fuelly - and even three successive tank fills of VPower saw zero difference in mpg and driveability..

So I stopped wasting my money...

Ethan,

Shell seem to be charging us Essex "kids" extra.

15 or 16 pence a litre is silly, when others such as BP don't have such a differential and sainsburys premium and Tescos are about halfway between. Asda only sell basic grade, but that is what the car gets if that is where i am when I notice or fuel light comes on.

Now, if i near a Tesco, it'll get momentum.

But I have noticed the engine does run smoother on "premium" of whatever type.

Although I believe that the engine management systems in modern cars is so good these days that the power difference is virtually unnoticeable.

This doesn't seem to make sense. A sophisticated EMS would be more likely to be able to exploit a higher octane fuel, mostly by dynamically altering the ignition timing.

I embarrassed myself a while ago by rubbishing a friends claimed improvement from higher than recommended octane, (I think on a Subaru Forrester) then realised I was parroting the "old school" story. A modern car might well be able to do this.

Ive given up even looking at the price I just fill up and go pay the bill. If I paid too much attention it may put me off using it and I do believe its better for my car than regular.

As the old joke puts it: "I don't know why people moan about fuel prices, it's always been a tenner hasn't it?"

I use it because I believe it will improve the reliability and durability of my VAG diesel engine. It must burn more cleanly and produce less soot because the frequency of active DPF regenerations decreased noticeably ( monitored using OBD port ) and subjectively the car seems to run better. Add to that the claimed extra lubrication it gives to injectors and the high pressure fuel pump. If it keeps my emissions system working it top condition Im happy to pay for it.

My sentiments exactly !

My Superb 1.4tsi runs better on higher octane petrol and if you are driving on a summers day with the windows down you can hear distant sound of pinking when going uphill and using 95 RON - I always thought that if making that noise it's not ultimately doing the engine much good. You can't hear the noise usually though as the soundproofing is too good. So as a rule I try to use higher Octane petrol - usually Tesco 99 ron which is only 5p litre extra.

I've found you also have to watch out in France now as well - many of the 95 pumps now seem to be E10(not all) but the higher octane ones are E5.

However I used to use Spritmonitor to keep an eye on my mpg (got bored after a while!) and there seems to be no real difference in economy between 95 & 99 ron petrol.

Since all modern cars are fitted with knock sensors the engine management should stop pinking occurring. If yours is pinking there is clearly a fault. It needs going to a garage to be sorted.

There is no fault - to be honest it's probably because it's fitted with anti knock sensors. Modern car engine management systems advance the timing etc to the limit to maximise economy/performance although this varies between manufacturers. I could hear a very slight distant pink with previous Octavia (NA 1.4 petrol) and current Superb 1.4tsi up a very steep hill with windows down (usually in France). Under normal driving you wouldn't detect this. It's not like the old days of a heavy rattle if your ignition timing was astray. To be honest no one else would be able to hear it, especially as the recent cars are so well soundproofed. I also think some of the French cheap supermarket petrol wasn't the best.

I used to tune Ford engines and adapt for different star petrol types so became rather familiar with the sound and manually set the timing right on the limit. It was at a time when the UK was moving from 2,3,4,5 star petrol types to just 2,4 star - all leaded then!

However my Superb drives better with higher octane petrol such as Tesco Greenenergy and it's still E5. You pays your money you takes your choice. Conversely it makes no difference whatsoever in Mrs BJ's 1.2 Panda.

I use Shell V power each third fill and can only comment that at almost 14 years old and 85000 miles, the Lambda reading this year was 0.999, last year and previous tests between 1.001 and 0.999, so the claimed cleaning additives seem to be doing a good job on the i30.

For the mileage I do now the price is affordable, it does seem to run slightly better too than on E10 .

The Lambda reading simply confirms that the system is adjusting the air:fuel ratio correctly - it doesn't tell you anything about the "cleanliness" of the engine, or otherwise.

All road fuel sold in Europe has to have the minimum cleaning additive specification - no fuel brand publishes their specification so no way of knowing if it's really any better.

There is no fault - to be honest it's probably because it's fitted with anti knock sensors.

So you are blaming the knock sensor for the pinking? How does that work, when operating correctly the knock sensors job is to prevent pinking? As I said earlier you must have a fault.

I think the knock sensor allows the engine to advance the ignition to just short of pinking but I think I hear that - it's not like the out and out rattle some of us would have been used to back in the day. I don't think I have a fault it's just me being over sensitive and it's only briefly when going up very steep hills indeed and you can't hear with the windows up. Car has now done 111k miles with no issue or any oil burning, it performs well and can do 50mpg on a run. I've heard this on both my Skoda petrol cars over the past two decades (I don't change cars very often) - usually going up the same steep high sided road in the Dordogne where we have been many times.

However I'll give up at this point.

Edited by Big John on 10/04/2023 at 18:09

It's always a good idea to compare prices at different gas stations and consider factors such as fuel quality and your vehicle's needs before deciding on which fuel to purchase.

Fuel in the UK is normally cheapest at supermarkets so not much checking to do, simply use the most convenient, we normally fuel when we shop.

Regarding quality all fuel sold in the UK has to meet the relevant BSEN standards so again no checking needed. There are only 2 types of petrol sold, the super which is 95 RON minimum and contains a maximum of 10% ethanol and premium which is between 97 and 99 RON depending on brand and contains a maximum of 5% ethanol.

Round these parts E10 petrol costs between £1.417 a litre (Asda) and £1.519 a litre (Shell) which is approx 46 pence a UK gallon. About 50% of petrol sold is bought from Supermarkets.

Some claim Supermarket fuel is substandard but since all fuel is delivered from the same distribution depots regardless of of its destination that is clearly nonsense. Anyway, if it was 50% of UK petrol cars would be regularly breaking down. We have used supermarket fuel pretty much all the time for almost 40 years now and not had an issue.

Just filled up at Shell Hitchin. Vpower is £1.65 compared to £1.39 for standard unleaded. This is plus 26p (or +19%) which seems more than it should be. I would expect +10% in line with the advantages. I use it primarily to avoid any maintenance issues of my Mini CooperS and the marginal improvement in mpg and performance.

I bought some E5 at Tesco last Saturday, £1.359 per litre. E10 is £1.289. The 7p a litre is 5.4% difference.

For the 4 years before the introduction of E10 the Caterham did about 35.15 mpg on 95 RON standard petrol. In the last 3 years I have been using E5 (mostly Tesco) it works out at 35.5 mpg.

The extra 0.36 mpg does not pay for the extra 7p a litre (current prices - was a bigger difference than that until recently). And the car does not run any better. But as I said before I feel more comfortable since some of the seals, "O" rings and pipes have an unknown ethanol resistance.