It says 98 ron fuel on the filler cap for a reason. But i see peoples issues. Im lucky i guess as there are loads of shell Vpower and tesco99 pumps near me. Must be a pain for guys with out pumps of 98+ron fuel near by

or 95 ron thats all i have ever.

Edited 9 July, 201114 yr by curs

Anyone been using 95 ron with no ill effect?

Just curious.

Yes, mine has been run on Shell 95 for all but 1 tankful of it's 7500k life. No issues.

It did seem to be a little smoother and slightly better pull with V-power. Economy was also slightly better, but not better enough to pay for the 8p per litre difference.

It didn't seem to like BP 95 as much and it really doesn't like Tesco 95

I'll check the cost of Tesco 99 and try some if it's a lot cheaper than V-power.

It didn't seem to like BP 95 as much and it really doesn't like Tesco 95 r.

Do you mean it liked bp but hated Tesco??

Sorry Mike, I misread your post. I get what You were saying now.

ive just averaged 27mpg over my first tank of 265 miles using Vpower. Wouldnt like to see the drop on 95ron fuel there are alot of short journeys though, and i dont drive like a granny

Funny that, my first tank at the moment is 27.5 mpg. What is your mpg up to now, hope it gets a little better

I wouldn't touch anything below 98 in my VRS, they just don't like it. Also I had an issue with my car misfiring after filling up with Tesco super, it's been fine since I went back to Vpower. Others have had the same issue with the momentum, seems either the vrs just doesn't like it or it's full of crap that's no good for the car.

Either way spending an extra few quid a tank on Vpower is certainly worth the money.

I wouldn't touch anything below 98 in my VRS, they just don't like it. Also I had an issue with my car misfiring after filling up with Tesco super, it's been fine since I went back to Vpower. Others have had the same issue with the momentum, seems either the vrs just doesn't like it or it's full of crap that's no good for the car.

Either way spending an extra few quid a tank on Vpower is certainly worth the money.

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i have heard nothing but good things about momentum and my vrs and a few other folk on here are having better mpg with momentum than v power. I tried both and performance wise i could not feel any difference, but i got a few more miles every fill up with momentum and as it cheaper and i get more mpg i stick to that. M

I wouldn't touch anything below 98 in my VRS, they just don't like it.

I think you need to get your car to the dealer if it "doesn't like" anything below 98ron. The official line from VW/Skoda is that it will run absolutely fine on 95ron with a negligible power difference.

presumably there will be a period of knocking etc as the ecu adapts to the lower octane fuel.

As I know when I had to put 95 in the car definatly didn't sound 100% for the first while

The other thing I have to go back to is why buy a supercharged Turbo'd car then complain about it having a taste for the finer fuel.

You want a fast car it'll drink expensive fuel, you want a fast women she'll want champagne.

I think you need to get your car to the dealer if it "doesn't like" anything below 98ron. The official line from VW/Skoda is that it will run absolutely fine on 95ron with a negligible power difference.

There is a power (and an economy) difference, I can feel it as I have been forced (on long journeys caught out) to put 95 in, deliberatley checked the economy (same driving, simple motoryway) and it lost 3mpg, which will offset the cost, the second time was at home, and some of my fave roads, the car felt "flat... sort of weaker) back to super, and its fast again... (see below for technical reasons) ... it does run "fine" , but the computer retards it to prevent detonation...

presumably there will be a period of knocking etc as the ecu adapts to the lower octane fuel.

As I know when I had to put 95 in the car definatly didn't sound 100% for the first while

The other thing I have to go back to is why buy a supercharged Turbo'd car then complain about it having a taste for the finer fuel.

You want a fast car it'll drink expensive fuel, you want a fast women she'll want champagne.

exactly... this engine was designed for 99 RON fuel... says so on the tin.... skoda quote, the ECU will retard the ignition with 95RON fuel to prevent "detonation" (look it up if you don't know what it is) so you will loose power and economy, as the ECU is taking away the peramiters the engine was designed around to allow it to be used with lower grade fuel... BUT it will run fine... BUT what did you buy it for? "drive it like you stole it!!" (sorry, a bit drunk........)

but concuur, higher octane=better.

incedently, concerning some of the above quotes, I have used tesco momentum with no issues. I generally use about 50/50 BP ultimate, and V-power...

Don't forget it takes two full tanks of the higher or lower octane fuel to alter the ECU settings fully. So, when you first fill up with something different in terms of octane rating it won't run properly for maybe several days until you've filled up again with the same stuff and run that through too. It's designed that way so you don't lose your settings if you have to fill up with something different out in the sticks somewhere.

Don't forget it takes two full tanks of the higher or lower octane fuel to alter the ECU settings fully. So, when you first fill up with something different in terms of octane rating it won't run properly for maybe several days until you've filled up again with the same stuff and run that through too. It's designed that way so you don't lose your settings if you have to fill up with something different out in the sticks somewhere.

Well if that is true my ECU is going to be cursing me !! I generally fill up with tesco 99ron after the beer/bread/milk run if I'm at home..but if I'm working away I fill up with whatever is going !! It will also be confused by my driving style cos I tend to take it easy on the motorway then drive considerably more briskly when I find a nice A/B road :p

1 tankfull of Tesco 99 is now installed, lets see how this goes.

It's 2p per litre cheaper than V-Power, making it only 5p more than 95.

Don't forget it takes two full tanks of the higher or lower octane fuel to alter the ECU settings fully. So, when you first fill up with something different in terms of octane rating it won't run properly for maybe several days until you've filled up again with the same stuff and run that through too. It's designed that way so you don't lose your settings if you have to fill up with something different out in the sticks somewhere.

I think you will find the knock sensor will retard the ignition and reduce the boost pressure in realtime when the engine is pinking.

So far, the Tesco 99 seems to be giving me about 2mpg more. This isn't conclusive yet though. The engine is running a bit smoother too, like it did when I used V-power.

Tesco momentum has high levels of ethanol in it , ethanol increases octane ie burns less easily but more importantly has less energy in it than petrol , so V power has the same octane rating AND a higher energy

So VPower should be better but 99 if you're nowhere near a Shell

My local Tesco was all out of Momentum 99 this morning

Tesco momentum has high levels of ethanol in it , ethanol increases octane ie burns less easily but more importantly has less energy in it than petrol , so V power has the same octane rating AND a higher energy

Tesco Momentum (Ingredients: http://www.tesco.com/Momentum99/productBenefits-specs.asp) contains 5% Ethanol in line with government 'recommendations' So does Shell v-power now. A statement from Shell last year: ‘Shell, like many other fuel suppliers, has begun blending ethanol into some Unleaded grades, including Shell V-Power at Stanlow, to comply with the legal obligations of the RTFO’ (Renewable Transport Fuel Obligation)

All fuels are a blended mix of chemicals with whatever fraction is used for petrol from crude oil cracking. Secondly, most fractions are complex mix of aromatics, hydrocarbons, ethers and alcohols. There is no pure petrol fraction. It is correct that different materials burn with different energies but 5% ethanol is going to have little effect on the energy output of the fuel.

Shell V power does not contain as much Ethanol as Tesco does , all uk fuels contain some ethanol now but there are many separate issues with that stuff with regards to water build up , corrosion etc etc

A lot of people will tell you Shell V power has far more knock resistance than Momentum as well

cue someone digging up the Thorney Motorsport article without noticing who sponsors their race cars

As you say the Thorney reports are going to be favourable as they sponsor them. Also they compare momentum with Tesco's own 95, so again, it's a no brainer. Back to Shell, a further reply when questioned as to the v/v ethanol content their reply was:

"Ethanol is being blended in gasoline up to a maximum of 5% volume, in order to respond to the Government's initiative to promote bio fuels, with the aim to reduce overall CO2 emissions and enhance energy supply security.

While Shell V-Power in the UK does contain ethanol. We have a legal mandate to blend a certain percentage of our fuels with a bio-component. Shell V-Power represents a significant proportion of our fuel volume in the UK and it is an important contributor in meeting our obligations under this legislation. Blending Ethanol into our fuels ensures that we meet the target set by the Renewable Transport Fuels Obligation (RTFO).

Dodging the answer but also implying they comply with the 5% level.

The water build up issue is actually a misunderstanding of what the problem was. Ethanol dissolves water so enables existing water in petrol tanks (usually just traces in the bottom below the take off point that have built up over time but caused no problem in normal use) to be absorbed into the fuel reducing it's combustibility (the worse problems occured where petrol stations first started selling ethanol blends from tanks that had not been cleaned properly and dissolved large amounts of residual water). The corrosion issue, I believe is an issue in higher ethanol blends as it undergoes oxidation to acetic acid over a period of time (bad if you are an infrequent user e.g in classic vehicles) This in turn, with the presence of traces of solubilised water, generates a corrosive mixture. Inhibitors are added but aren't as effective as they should be. There was also issues with seals in old engines that aren't compatible with new fuels

My observations of running 95 in my vrs are that it's stutters and miss fires when cold until the ecu adjusts it to run smoothly, slightly lacking in power from a stand say at a junction etc, only trouble is that so far I have filled up twice and both garages didn't supply 98 or 99. A little homework and I have found the place near me that do so in the next few fill ups I should see a difference!!

Can honestly say i use both shell unleaded and shell v power and to be real honest i see very little difference, well not enough to say wow i know what to put in my car now, i never get a different sounds from the car, and when i need it all is there, but i do say that i never use tesco and asda petrols, just think shell is the best ive used on all my cars, but i am going to try bp at sometime......

I think you will find the knock sensor will retard the ignition and reduce the boost pressure in realtime when the engine is pinking.

That's correct but it won't alter the ecu's main operating parameters for the octane fuel you have just put in. At least not right away. So for example if it's 95ron (instead of 98ron on one fill up) the sensors lower performance at the sharp end as it detects the higher operating temp and different bang of the lower octane fuel and the alter combustion process. But, the ecu settings essentially remain the same overall, set for 98ron until it detects a prolonged change in the combustion condition. This will usually be 2 tankfuls as per what the manual says. Either way no harm will come to the engine, just minor performance variations and mpg differences as you guys are saying.

Best policy is always to stick with the same octane rating fuel and preferably the same brand to ensure best performance otherwise the ecu doesn't ever stop learning and may not give best performance.

Edited 16 July, 201114 yr by Estate Man