Tesco fuel

geekgirl

I was told today that Tesco fuel has more detergents etc... in it making it lower quality. This in turn can make your engine underperform and 'pink'. Is there any truth in this? Has anyone noticed their car pinking or underperforming? Is this just an urban myth?

mrtg0525

It really depends which fuel you're talking about.

I'm using both the 95RON unleaded and their 99RON unleaded on a regular basis, the latter in a turbocharged Mazda RX-7 which happens to be a tad picky when it comes to fuel quality.

I use the 95RON fuel mainly in my motorbikes that are generally more powerful per capacity than a car and haven't noticed anything adverse compared to, say, Shell (which is my other fuel of choice).

I've heard the comments regarding detergents a few times, but they're supposed to affect the O2 sensor and eventually disturb the readings that the engine management gets from it...

geekgirl

Thanks for the reply, excuse my ignorance but I don't know the difference between 95RON or 99RON.

It wasn't specified when my friend told me, but I don't think she knew any difference either.

I have always gone for the cheapest thinking that petrol is petrol is petrol....obviously there is more to it.

Cheers.

xzibit

The RON figure is the octane rating of the petrol. The higher the rating, the higher the combustion point I belive.

Most cars are fine on normal 95RON unleaded. Some, like mine, need super unleaded 97,98,99RON. Inside my petrol cap it says "use 98RON Super Unleaded".

With regards to the detergents, this is to do with the cleaning of your fuel system and engine. Shell Optimax (now V Power) has good cleaning properties, and a high octane rating for example.
I have heard Tesco fuel has a low detergent level, and is crap for cleaning your engine, and many people I know refuse to use it.

I have both a Tesco and an Esso petrol station near me, and the prices are the same, so I choose Esso everytime.

mrtg0525

Well, unfortunately petrol isn't always just petrol. That said, most modern cars with the exception of certain high-performance (and certain Japan-only) models are designed to run on standard (95RON) unleaded.

Certain high-performance engines can either take advantage of or require petrol with higher octane rating in order to squeeze more power out of the engine. This is usually to avoid pinking/knocking/uncontrolled detonation.

In the context of the detergent issue and other similar problems, I've mostly heard this for the higher octane rating.

Oh, and to make matters even more confusing, what we in the UK refer to as standard unleaded (95RON) is often labelled as Super unleaded in continental Europe as they often have a lower grade petrol (91RON, from memory) available as well. It's not really a good idea to put 91RON into a car that wants 95...

Here's a wikipedia link that tells you more than you ever wanted to know about fuel octane ratings:

http://en.wikipedia.org/wiki/Octane_rating

bestyman

Well the proof of the pudding so to speak.....
Since becoming a tesco points addict a few years ago I have put 50,000 miles on an astra 1.7 turbo diesel and 30,000 on a mondeo 2.0 petrol using 99.99% of the time tesco fuel with no problems at all.

leeshowes

I dont know if this is in any way linked to RON!!!!

Myself and 3 colleagues at work have all been experiencing engine problems since using supermarket petrol.

One put it done to an old car,
another down to being due for a service and again the car being older

But this weekend my 2 year old diesel Merc A170 and a colleagues 3 year old petrol Fiat Punto both has serious engine failures.

The Fiat even failed its MOT on Emmissions.

Both cars have been bunny hopping at low speed and then not getting much past 60 when the pedal is floored!!!!

My colleagues mechanic has told him his vehicle needs a new fuel sensor and a full service to try to solve the problem.

It was the mechanic himself who asked whether he had used Tesco Petrol. Apparently Tesco's new Green Petrol contains something call Bioethanol and it is this that is causing damage to some vehicles. The fuel is produced by a company called Greenenergy. (A list of all the Tesco Stores currently stocking this fuel is on the Greenenergy website)

The thing that baffles me is that i use Diesel!!!

Has anyone heard about this?

Has anyone else noticed this problem?

Does anyone with a technical mind know if my Diesel car is affected by the same thing?

Is it anything to do with RON???????

mrtg0525

From your description it actually sounds more like water in the fuel than anything else, but then again this is a third-hand experience... The only reason for the problems other than water in the petrol (because ethanol binds water, but that should be OK as it's an old trick to avoid getting water into you fuel system) is that some of the seals didn't work with ethanol. My other half had that problem but she was running her old Jeep on E85 in the US (85% Ethanol, 15% Petrol) so that's a different problem.

I've been using Tesco's 99RON fuel in my RX-7 for a while and it's working fine, but then again rotaries are notorious for burning anything that looks like fuel as long as it's got a high enough RON rating. That particular fuel is confirmed to be manufactured by Greenergy; not sure about the 95RON one.

As you run a diesel, it should be a problem if they mix in a little recycled chip fat . And no, it doesn't have anything to do with the RON number as that's a measure of how hard the fuel is to ignite/self-ignite (self-ignition aka detonation is bad) and that's actually a desirable quality in the Diesel.

Takecareofthepennies

Seems this problem is not so limited, at least around the South-East:

http://news.bbc.co.uk/1/hi/uk/6405051.stm