Over the last few weeks our local Shell garage had been out of Optimax every time I went there so I had nipped across the road & used Tescos Super, always meant to try it & its got a high Octane rating. about that time the car started being a bit difficult to start from cold, missed a lot for the first 30- seconds unless you held it at about 2000 rpm.

I have now reverted to Optimax because its available again & the car is starting fine again after about 120 miles of Optimax, it might just be a coincidence but it I think prooves that there is a difference between the various fuels & just perhaps the stories of Supermarket fuel being suspect might be true. I will addd that the Octavia is heavily modified & was mapped on Optimax which probably has a bearing, standard cars can run on just about any fuel so the differences are probably not as noticable but are these fuels sub standard ??

This is only a personal observation & is in no way intended to be advice from an expert & should be treated as such

I'd be surprised if the Tesco Super was anywhere near the high Octane rating of a proper Optimax, probably looking at 97, perhaps 98 RON for Tesco Super, whereas the Optimax will be knocking at 100 RON or even higher perhaps.

Tesco super is 99ron in Stuart's part of England AFAIK.

Tesco super is 99ron in Stuart's part of England AFAIK.

thats what it says on the pump, Tescos J9 of the M3

I think it has been proved that BP ULTIMATE is the highest Octane fuel. I use BP diesel myself.

I used Tesco 99RON a while back and had previosuly blamed it for my car running badly. Since then I've found a split hose so I'm up for trying it again soon.

I have used Tesco 99 Ron since it first became available, and cannot fault it, a real improvement over others, also it is clearly marked 99 Ron on the pumps.

Used tesco 99 ron on my roadster and it ran fine. Before anyone says anything too, the engine is running close to max tolerences so really it should be given the best, but i didnt notice any difference between the two (tesco and optisplurt)

i have used 99ron tesco fuel ever since it appeared in oxford, i did have a problem with cld starts but it turns that was due to my disconnected secondary air feed and since that has been reconnected it as stopped

Coincidence or not, I've been filling up with Tesco Super RON99 since it came out and I too am now suffering from really bad cold starts. Not going back to the Optimax fold yet, but I do have to agree that with Optimax it felt like it was running 'smoother'.

I have used BP Ultimate from new. I have NEVER seen any smoke at all, even putting your foot down uphill. I average 50mpg (hard driving and round town) and have just averaged 69mpg, Yeah, 69mpg on a run to Liverpool. Set the cruise at approx 70mph and this was over 55 miles on the M6. Unreal.

I use Tesco 99 as much as possible and haven't had any problems with cold starting, although it is slightly 'lumpy' at the 1500-2000rpm mark. That could be the Jabba remap though, as they got 240bhp on a standard remap with boost controller when running on 99RON... They told me to turn the boost down a bit if using anything less

Having used Optimax on my previously (heavily modified) Rover turbo and seeing the cleaning effect it had internally on the pistons I decided to use it from day 1 on the Octavia. I have now done over 11k miles from new and only ever used Optimax.

There is a big fuel test in the January edition of EVO magazine. It compares all of the common fuels on a BMW M5 and a Mk V Golf GTI. The results were very similar for the M5 but noticeable differences were seen on the Golf:

Shell 95: 205bhp/234lbft

BP 95: 204bhp/242lbft

Shell Optimax: 209bhp/242lbft

Tesco 99: 212bhp/242lbft

BP Ultimate: 212bhp/252lbft

Sunoco Race Fuel: 218bhp/248lbft

Although BP Ultimate gave the best figures they concluded that Optimax was best over all when you consider smooth running, performance and cost.

Have always used Tesco's diesel and petrol (for the Smart). Never had any problem, and on the Octavia 45.6 mpg over 36,000 miles.

Methinks a lot of wishful thinking going on here?

Methinks a lot of wishful thinking going on here?

Unless you happened to be one of the poor sod's behind me this morning when i pulled ouit rather briskly.....

Yes' date=' i drive a re-mapped PD130, but I've never managed to obliterate my view of [b']all three lanes[/b] like i did this morning.......Engine is about 150miles left on a tank of Tesco Derv............

Have always used Tesco's diesel and petrol (for the Smart). Never had any problem' date=' and on the Octavia 45.6 mpg over 36,000 miles.

Methinks a lot of wishful thinking going on here?[/quote']

If your Octavia is a diesel then that mpg figure isn't particularly good.

I will addd that the Octavia is heavily modified & was mapped on Optimax which probably has a bearing' date=' standard cars can run on just about any fuel so the differences are probably not as noticable but are these fuels sub standard ??

[/quote']

Having read this, I think that might be true. I had no idea that the octane rating had more to do with the compression ratio it's suitable for than the actual energy released by burning it. You learn a new thing every day...

If you have vagcom then it's easy to check the difference between different fuels by logging the timing retardation. You can then adjust the timing with appropriate software to get the most from your fuel of choice and keep the engine within safe limits.

Edit - This only applies to petrol cars.

Readers of the Daily Telegraph (Saturday Edition) in the Honest John column will see that he allways endorses Shell fuels ,he states that it contains more detergents that its rivals

45 odd mpg is actually pretty good for a diesel if it's town mileage, as you can see he says over 36,000 miles so he will obviously get a higher figure on longer individual runs, you'd never get close to that with a petrol engine over the same mileage, trust me I have quite a few cars on my cab fleet!! (both petrol and diesel)

As for the fuel, my uncle works on security at the worthing refinery, in the old days when supermarkets first started selling fuel there was a difference, It wasn't filtered as well and contained more particles to clog your filters, he (illegaly) bought some samples round once and showed me, it was shocking to see the cloudy colour of supermarket fuels with bits of black tar like substance in it! - however things have changed now.

All the tankers - BP, Shell, Tesco, Sainsburys etc etc all fill up from the same tanks, where the fuel is then delivered directly to the forecourts - no stopping to add chemicals or detergents etc, they all use the same fuel as it comes out of the tank with the chemicals and detergents already added. Think about it - Despite BP's advertising claims all they are interested in is profit - if they all band together and include supermarkets in their bulk buying they can all get it cheaper!

the only differences that can occur are with the cleanliness of the tankers, forecourts tanks, pipes etc. so it might be that Shell or BP maintain their forecourts better than Tesco or Sainsburys, but thats it. I never have any problems with Tesco fuel.

All the tankers - BP, Shell, Tesco, Sainsburys etc etc all fill up from the same tanks, where the fuel is then delivered directly to the forecourts - no stopping to add chemicals or detergents etc, they all use the same fuel as it comes out of the tank with the chemicals and detergents already added.How about BP Ultimate then ?

All the tankers - BP, Shell, Tesco, Sainsburys etc etc all fill up from the same tanks, where the fuel is then delivered directly to the forecourts - no stopping to add chemicals or detergents etc, they all use the same fuel as it comes out of the tank with the chemicals and detergents already added.How about BP Ultimate then ?

Most likely from the same tank as Shell Optimax or Tesco 99 ron, therefore they can all claim to have added stuff!!

All the tankers - BP, Shell, Tesco, Sainsburys etc etc all fill up from the same tanks, where the fuel is then delivered directly to the forecourts - no stopping to add chemicals or detergents etc, they all use the same fuel as it comes out of the tank with the chemicals and detergents already added.How about BP Ultimate then ?

I was told that various chemicals are added on the gantry as the tankers are filled, for instance LRP is simply super + a few additives & its cheaper than super (work that one out) but Im happy to be corrected on that one as it was only via a third party although one that should be reliable

DONT BUY LRP just in case I am mis informed

I was told that various chemicals are added on the gantry as the tankers are filled

Sorry Stuart, but as a tanker driver..............No NO No, it does not happen.

Imagine in if it did, we would be going back to the days, long, long ago when they asked you at the pumps if you wanted any shots in with the petrol (Upper Cylinder Lubricant) Usually one shot per gallon.

Now I do feel old.........................Sits back and waits for Des to comment:)

I was told that various chemicals are added on the gantry as the tankers are filled,

Further to Beretta's comment, I would add that putting the additives in at the time of filling the tanker would not give sufficient mixing for there to be a consistent concentration of additive throughout the batch, and so the fuel would be of decidedly variable quality when delivered. I don't think they'd be able to sell it if it wasn't loaded on the tankers ready-mixed, after being properly quality controlled.

But then maybe I'm giving the fuel companies more credit than they deserve...