102 RON petrol!

[Yandards 0]

Either way, I regularly get 30 or 40 more miles out of a tank with Super, which negates it's extra expense per litre.

 

I have also just managed a 37.1mpg run on a leisurely commute back to home over 40 odd miles. This is from cold, with a few miles of twisties, some full throttle out of a couple of roundabouts onto dual carriageway, 35 miles on the motorway at 56mph and a mile of traffic round Chiswick.

 

Not bad for 170k mile 2.9 litre!

 

That's very good indeed!

 

I wonder what the extra mileage from the Super unleaded can be attributed to? With the same tank volume and driving style, I don't see how it's possible personally, but I'm not disputing your findings, that's very impressive :D

 

Super should burn slightly faster/hotter producing a little more power for a given quantity of fuel when compared against a lower octane rating.

[demons uk 0]

I drive a standard S3, and always use V-power, pretty sure i read the tesco super is just 95 ron with some bits added to it to bring it up.

 

crappy supermarket petrol isn't going anywhere near my car, V-power gives a far cleaner burn if nothing else.

[dan 0]

Super should burn slightly faster/hotter producing a little more power for a given quantity of fuel when compared against a lower octane rating.

I agree, the car doesn't know (or need to know) its being more efficient... it just is

[ANDREW 30 0]

I drive a standard S3, and always use V-power, pretty sure i read the tesco super is just 95 ron with some bits added to it to bring it up.

 

crappy supermarket petrol isn't going anywhere near my car, V-power gives a far cleaner burn if nothing else.

 

I read a fuel review a couple of weeks back and they had tested the tesco 99 against v power and all the others the tesco 99 and v power came out on top but there was nothing between them!

[dan 0]

Where I live its very hard to get anything other than regular 95 RON, so I'm always on the look out for good off the shelf additives. The thing is usually there is no information/guidelines on how much the RON will increase if indeed it boosts it at all. anyone know of a good additive I can buy?

[KipVR 1]

I would say though that the tension of the knock sensors has no bearing on the amount of timing it can advance/retard by because it's fixed to 12 degrees maximum.

 

Yeah I didn't type that very well Kev, I didn't mean that the torque of the knock sensor governed the extents to which the ecu can retard or advance the ignition, it just alters the sensitivity of the knock sensor itself. So basically it's important to torgue it up to the correct setting or it won't pick up the pinking correctly which in turn misleads the ECU.

 

Really i was just demonstrating that there is a direct correlation between the knock sensor and the ECU's timing. Other imputs are from the temp sensor and engine speed.

[rob1234 0]

Super should burn slightly faster/hotter producing a little more power for a given quantity of fuel when compared against a lower octane rating.

 

Octane rating doesn't have anything to do with the burn rate or temperature - it's the measure of resistance to pre-ignition. However, the only thing I can come up with is that the super has a (coincidentally) higher energy density than regular. To get 37mpg I am staying well away from full throttle (well 99% of the journey :-)), so octane shouldn't make any difference to the timing...

 

A bizarre, but repeatable, result.

[KipVR 1]

A good guide about the basics of knocking etc....

 

http://www.streetrodstuff.com/Articles/ ... Page_4.php

[Kevin Bacon 5]

I drive a standard S3, and always use V-power, pretty sure i read the tesco super is just 95 ron with some bits added to it to bring it up.

 

crappy supermarket petrol isn't going anywhere near my car, V-power gives a far cleaner burn if nothing else.

 

Tesco 99 is refined to 99, but contains 5% Bioethanol. It's a very good fuel. My VRT prefers it to V Power.

 

It was Optimax that was refined to 95, but with boosters added :D I believe V Power is refined to 99 aswell, which means it doesn't "go off" in the underground filling station tanks like Optimax used to.

[Kevin Bacon 5]

A good guide about the basics of knocking etc....

 

http://www.streetrodstuff.com/Articles/ ... Page_4.php

 

Good link!

[Conker 0]

I defnitely get a couple of extra MPG on V-Power too. The last time I did a proper full tank test, the overall cost per mile was exactley the same between super and normal unleaded.