Tesco 99RON fuel and C32 issues

[whestworld]

Hi

about a year ago I switched over to Tesco 99Ron because I had heard good reports about it and also I had moved to within 1 mile of a Tesco petrol station selling the stuff. I had been using V-Power in my C32 previously.

The C32 was Ok for about 2-3 weeks using the 99RON then I started to develop a few problems. The accelerator pedal felt a bit 'spongy' but more seriously while accelerating to 60mph it would just hesitate and not want to go any further. The engine sounded terrible all the time and I could hear a high pitch whistle all the time.

I thought it was the coil pack/packs or something else as the forums were telling me that at 60mph if the C32 hesitates and then goes lumpy it is most likely that.

Anywho... I didn't get it serviced because it was OK if I drove it below 60 and anyway I was working abroad a lot so I didn't have the time to get the car looked at.

So I'm back. Filling up with Tesco 99 but my last fill was with V-power (my old stuff) and guess what....the car is fine again. It accelerates past 60mph, the pedal feels firm and it is a joy to drive again. The engine sounds fine and the whistle has gone.

What the hell do they put in Tesco 99 Ron? or is it because the C32 doesn't like higher octane fuel?

 

[Roamer]

Like you I live about a mile away from a Tesco so I tend to always use their high ron fuel but I've never noticed any hesitation around 60mph or any real difference when I fill up with V-power. I've had the car for about a year now and can't think of a problem like that, even when my tps was failing.

Not sure that helps you at all, just my expereince.

 

[markjay]

Have you been filling up at the same Tesco petrol station? If so then it might be a specific issue with the fuel or tanks in that particular station rather then an issue with Tesco 99RON as such?

 

[whitenemesis]

V Power is also 99RON ...

 

[markjay]

From Wikipedia who know everything:

'In the United Kingdom and Denmark (where Super Unleaded must be a minimum of 97 RON), V-Power has a rating of 99 RON (whereas V-Powers' predecessor Shell Optimax was rated at 98 RON). There is one other 99 RON fuel available in the UK, namely Tesco MOMENTUM99.'

 

[whestworld]

mmmm.
It's the same station I fill at and pretty much the same pump - bad habits

After my experience (whatever was causing it) I don't really fancy going back to Tesco for a 1.2p/ltr saving. I like V-power and the car feels great.

I remember back about 20 years ago people used to say that supermarket fuel contained more detergents than the good stuff...so you were paying for detergents and not petrol....is that still true?

 

[whestworld]

I pulled this off the net...and this is what my C32 was like on Tesco 99.

'My Type-R is tuned on V-power, running it on anything else and it feels crap. Throttle response is awful, doesn't like to rev as cleanly, not as much torque etc.'

 

[Riverside Red]

I ran my S2000 on both V Power and Momentum and never noticed any difference once used BP Ultimate and it was dreadful. SLK will live on V Power and Momentum too.

RR

 

[Neil Mackay]

Intercooler pump maybe? I've run mine on momentum for 18 months with no issues at all.

 

[markjay]

My lowly C180K is fed a strict diet of Shell V-Power and BP Ultimate, nothing else, and it can't tell the difference.

 

[Dieselman]

How could a brand of petrol make the engine sound whistley..??

There is probably a fault with the car, it isn't the fuel.

 

[Kal_c63]

Sounds like too many issues just to be fuel related.

 

[DSB SL AMG]

i also mostly use Tesco momentum....never had a problem, i would recommend you get your car checked out by a local good indie. i do occasionally use V-power with no noticeable difference...

 

[gazc32]

running a c32 on 99ron fuel will have no benifit unless its been mapped on 99 ron. after 7 years of running jap turbos im glad to get away from the stuff, jap cars do need it because there set up to run on 100 ron standard . the only benifit of running the higher ron fuel is its less prone to detonation thus the ecu doesnt keep pulling the timing and you keep running peak power, but if the car is set up on 95 there wont be any det in the first place running 95 and so timing isnt being pulled ,it certainly wont do it any harm but its not doing anything 95 doest do either

 

[markjay]

Modern engines automatically adjust to accommodate for higher-lower Octane (knock sensor and ecu advance or retard the ignition as necessary).

But you are correct that in most cases if the engine is not tuned this will only translate into a minute improvement in bhp.

Said that, the car should return better mpg with the higher Octane fuel.

 

[Neil Mackay]

Id still suggest its an intermittent intercooler pump issue! Sounds like when the charger clutch engages the pump doesn't want to play so the ecu goes into limp