Super market fuel V Branded fuel.

[CanucksTraveller]

Way back when I had my Impreza specifically mapped to run at the edge of performance on Shell Optimax as it was then.....

You can "map" a car to run on a specific brand of fuel? I've not heard of that, what does it involve and how does it work?

 

[Drago]

You can map some turbo models to advance the ignition. A few outlets sell 101 RON (Japan's standard rating) to allow some of these highly strung Japanese hand grenades to run at full power.

 

[fixedfixer]

You can map some turbo models to advance the ignition. A few outlets sell 101 RON (Japan's standard rating) to allow some of these highly strung Japanese hand grenades to run at full power.

I run a cheapo Suzuki and so it is obligatory to feed it the cheapest fuel that can be found leaving surplus for a new bike

Oh yes, and in Aberdeen we make any Yorkshireman look like a spendthrift

 

[Sea of vapours]

You can "map" a car to run on a specific brand of fuel? I've not heard of that, what does it involve and how does it work?

You're not mapping for a brand of fuel, you're doing it to run better at a given octane rating. Mapping is the term for changing the firmware in the ECU (engine control unit computer) to modify the ignition timing. Basically, plug computer into port and transfer code across to replace existing code - and hope nothing goes horribly wrong. (Not something to do at home, as they say.)

 

[Drago]

I buy the cheapest as well.

 

[screenman]

I spend £120 a week on fuel, I buy cheapest. Used to be £100 pre June.

 

[Pale Rider]

You're not mapping for a brand of fuel, you're doing it to run better at a given octane rating. Mapping is the term for changing the firmware in the ECU (engine control unit computer) to modify the ignition timing. Basically, plug computer into port and transfer code across to replace existing code - and hope nothing goes horribly wrong. (Not something to do at home, as they say.)

I had a Focus diesel remapped for a bit more performance, which also led to improved economy.

Sounds like magic, but as the guy who did it explained to me the factory map is conservative, partly to take account of poor fuels in some markets.

A remap of a car used in the UK takes advantage of the generally good quality fuels we have in this country.

 

[marknotgeorge]

Quality control at supermarket petrol stations seems poorer. They pop up in the papers after diesel comes out of petrol pumps or vice versa. Worst I've had is slight uneven running on a fussy car a few cars ago. And a relative suffer an upset stomach after a dud salad.

Local branded station matches the prices of the nearby supermarket so what's the incentive to switch?

The local Esso garage is always a couple of pence more than the Sainsbury's further up the road. And the Sainsbury's the other side of town is a penny or two cheaper still, presumably to compete with Asda. And most fuel stations in Derby are cheaper than in Burton - cheaper than a fair few places, actually.

 

[User33236]

Back in the mid 90's I called my loca Fiat dealer to book my 6 month old Punto for a check up as it was pinking, particularly on inclines. The receptionist asked if I filled my car at the local Tesco store to which I replied 'yes'. I was then told that they were having numerous reports of the same issue and suggested switching fuel. The tank was already close to empty so I switched to Esso on the next fillup and, almost overnight, the pinking disappeared. Never been back to a supermarket since.

With the limited number of miles I drive per year it's hardly worth bothering about Esso / Texaco / Shell etc being a penny or so dearer per litre.

On the other side of the coin I seem to recall Strathclyde Police claiming to have valve seat damage to their fleet of cars using a particular formulation of Shell petrol.

 

[User33236]

I had a Focus diesel remapped for a bit more performance, which also led to improved economy.

Sounds like magic, but as the guy who did it explained to me the factory map is conservative, partly to take account of poor fuels in some markets.

A remap of a car used in the UK takes advantage of the generally good quality fuels we have in this country.

I got a remap file for my Mustang from a bloke in Florida than took into account the K&N cold air intake I fitted and took into account the differing conditions and fuels in the UK vs USA. This too improved performance whilst also increasing mpg to the scary heights of 19 mpg for the 16 to 17 mpg the stock car had given.

 

[Moodyman]

I spend £120 a week on fuel, I buy cheapest. Used to be £100 pre June.

By heck! You must either do big miles or drive a guzzler or both.

 

[NorthernDave]

I can only speak from my own personal experience:

I had a Citroen C3 1.4 HDi 8v, which for most of it's life was run on Tesco diesel, with the occasional tankful from Asda or one of the 'brands' (either Shell or BP). At a rough guess I'd say it was around 80% of the fuel came from Tesco, with the others fairly evenly split over the rest. It never missed a beat in over 100,000 miles.

Then Morrisons started doing a promotion which made it worth going there to fill up. Within two tankfuls I'd noticed that the tickover was getting increasingly lumpy and the engine was slightly hesitant under load. I didn't put the two together immediately but after a month or so spoke to the garage who look after the car and they checked it over and the first thing they asked afterwards was where I'd bought the fuel from.
When I told him he smiled and recommended that I run a tankful of Shell V Power diesel through it and then switch back to Shell Fuel Saver diesel after that and see how things went.

Before the car had finished that first tank of V Power diesel it was running normally again, and continued to do so until I sold it a couple of years later. Although I'll still buy fuel from other supermarkets I haven't bought Morrisons diesel since.

 

[screenman]

By heck! You must either do big miles or drive a guzzler or both.

Big miles.

 

[Drago]

In fact, thinking back about 25 years, I once stopped for fuel in my Silver Wing Interstate, and it ran like it had an HT missing until I topped it up with fuel from elsewhere. Pretty sure that was Texaco, hopefully not the one the OPs missus works at.

 

[Moodyman]

I understood that supermarket fuel was poorer quality vs Shell, Esso et al but this was circa 20 years ago. I thought the gap had closed enough to make it nigh on negligible now for ordinary cars.