Warning POSSIBLE Tesco 99 Poor fuel problem

[Andyuk911]

Just a heads up but I am 99% sure Tesco have a problem with the 99 Fuel.

I filled the wife's 2008 Renault 1.2 TCE from almost empty, and after 20 miles the car went into limp mode.

I have had it checked, and no faults are found.

Car is now running rough on tickover and lacks power, I assume the ECU has backed everything off.

I am certain the problem is the Super unleaded bought from Tesco Sidcup and no faults with the car.

[Mafioso]

Surely putting Super Unleaded into a 1.2 litre is the reason?

[NiceCupOfTea]

Mafioso said:

Surely putting Super Unleaded into a 1.2 litre is the reason?

Why would put high octane fuel in a non-performance engine make any difference at all? If he put 95 in a 98 only spec engine then yes.

[Mafioso]

NiceCupOfTea said:

Mafioso said:

Surely putting Super Unleaded into a 1.2 litre is the reason?

Why would put high octane fuel in a non-performance engine make any difference at all? If he put 95 in a 98 only spec engine then yes.

I've heard that it has the opposite effect. Just what I've heard.

ETA: Something to do with compression ratios?

Edited by Mafioso on Saturday 28th November 17:41

[TheEnd]

It can't be in limp mode, limp mode is a choice made by the ecu when it registers a problem, and if it registers a problem, it'll note it down.
More likely your precious car is ill.

[kambites]

What reason do you have to believe it's the fuel not just the engine being, well, French?

[varsas]

So it's in limp home mode, but there's no faults stored? That's very odd, you would assume the fault that is causing limp home mode to be activated would be stored...

[Andyuk911]

All valid points ... But I took a vid of the device pulling the data ....

Reason for the Super unleaded for the uneducated, more cleaning agents and even in a 1.2 Turbo you can feel the difference ...

[Zad]

Surely the reason for super unleaded is a higher octane, and on a car with a knock sensor it will get more power out of it? On an engine not equipped with a knock sensor it will just work as "normal".

[Andyuk911]

Zad said:

Surely the reason for super unleaded is a higher octane, and on a car with a knock sensor it will get more power out of it? On an engine not equipped with a knock sensor it will just work as "normal".

Correct, the Clio's engine is the latest and advances the ignition.

[TheEnd]

Andyuk911 said:

All valid points ... But I took a vid of the device pulling the data ....

Our point is it's most likely something like a misfire, and not limp mode. Most ECUs have a tolerance built in too, they need to see a fault for x amount of seconds first, or an intermittent fault appear over 2 consecutive drive cycles before they will log the fault. Take it for another drive, and see if it happens again, and check the codes again. See if anything turns up.

[Rollcage]

I would have thought crappy fuel would have manifested itself earlier than 20 miles. Probably just coincidence.

[Chr1sch]

I would doubt it's the fuel,sounds like an issue with the cat maybe?

[AndrewW-G]

Andyuk911 said:

Zad said:

Surely the reason for super unleaded is a higher octane, and on a car with a knock sensor it will get more power out of it? On an engine not equipped with a knock sensor it will just work as "normal".

Correct, the Clio's engine is the latest and advances the ignition.

But only if there is an ECU map for the higher grade fuel, otherwise it will just run at the higher tollerance end of its standard maps. Most cars setup to use higher octance fuels, dial back the ignition timming amongst other things to cope with lower grade fuels and have the ability to do it built into the ECU/map. I'd be interested to see a dyno print out of a 1.2 clio on standard and super unleaded.

Edited by AndrewW-G on Saturday 28th November 17:55

[Andyuk911]

I understand the thoughts you are all having.

The car since new has run 'sweet'

Obviously the only way to prove this is to sample the fuel ..

The 20 miles was approx.

I will try and run the tank out dry and switch to shell ... I can then only report back if the car returns to it's normal performance.

I still feel if you plan to use Tesco 99, play it safe for now .......

If the car had any problems I am sure they would have fixed it .... they suggest it is the fuel too

[Andyuk911]

AndrewW-G said:

Andyuk911 said:

Zad said:

Surely the reason for super unleaded is a higher octane, and on a car with a knock sensor it will get more power out of it? On an engine not equipped with a knock sensor it will just work as "normal".

Correct, the Clio's engine is the latest and advances the ignition.

But only if there is an ECU map for the higher grade fuel, otherwise it will just run at the higher tollerance end of its standard maps. Most cars setup to use higher octance fuels, dial back the ignition timming amongst other things to cope with lower grade fuels and have the ability to do it built into the ECU/map. I'd be interested to see a dyno print out of a 1.2 clio on standard and super unleaded.

Edited by AndrewW-G on Saturday 28th November 17:55

The Engine ..

http://www.renault.co.uk/about/innovations/TCE_100...

[AndrewW-G]

Andyuk911 said:

I will try and run the tank out dry and switch to shell ... I can then only report back if the car returns to it's normal performance.

You do know it all comes out of the same tap at the refinery?........ If it is the fuel its more likely a cockup at the petrol station than the refinery.
Given the current weather it could have been damp in the electrics, if it were me I’d be making sure I had the answer before slating a company that may not be at fault, especially one as litigious as Tesco

[Andyuk911]

BIANCO said:

How are you 99% sure it’s the Tesco fuel? It far more likely to be your car that’s the problem not the fuel.

Been checked .... but note the thread title .. POSSIBLE ...

[AndrewW-G]

Andyuk911 said:

AndrewW-G said:

Andyuk911 said:

Zad said:

Surely the reason for super unleaded is a higher octane, and on a car with a knock sensor it will get more power out of it? On an engine not equipped with a knock sensor it will just work as "normal".

Correct, the Clio's engine is the latest and advances the ignition.

But only if there is an ECU map for the higher grade fuel, otherwise it will just run at the higher tollerance end of its standard maps. Most cars setup to use higher octance fuels, dial back the ignition timming amongst other things to cope with lower grade fuels and have the ability to do it built into the ECU/map. I'd be interested to see a dyno print out of a 1.2 clio on standard and super unleaded.

Edited by AndrewW-G on Saturday 28th November 17:55

The Engine ..

http://www.renault.co.uk/about/innovations/TCE_100...

not sure what thats supposed to mean, other than it's an engine, nothing on there about the fuel its supposed to use of the adaptive functions of the ECU

[Andyuk911]

AndrewW-G said:

Andyuk911 said:

I will try and run the tank out dry and switch to shell ... I can then only report back if the car returns to it's normal performance.

You do know it all comes out of the same tap at the refinery?........ If it is the fuel its more likely a cockup at the petrol station than the refinery.
Given the current weather it could have been damp in the electrics, if it were me I’d be making sure I had the answer before slating a company that may not be at fault, especially one as litigious as Tesco

I agree .. note POSSIBLE !

The car is always garaged and thus would not be damp ... the car is 'relatively' new ..