Fuel

[VioletCat]

Firstly HPY everyone
Secondly sorry if this has been covered before, I went back 20 plus pages and could not find anything so asking the group.

What fuel does everyone use?
In an old K series I ran 99 all the time but I feel my 420r was fuelled with 95 before picking it up for the first time. Since then I have refuelled it with 99 and it didn’t like it!
I understand the ECU has to change etc but has anyone else had this experience?
It was almost as if I had lost a cylinder or two for the drive home with a warm engine but fresh fuel. I believe it’s settling down now.
Also it only took 20 litres when I believe it has a 34 litre tank!

Any help/advice would be most welcome

Thanks,

[VioletCat]

DCL said:

The Duratec installation in the Caterham is quite sensitive to fuel. Not to so much the octane rating but some fuels can cause vaporisation in the fuel rail. Best cure is to fit a fuel line return and regulator, but if not, I would avoid generic supermarket fuels. The winter months can be particularly bad and I would go for a good quality branded fuel such as BP ultimate, or shell V power. I'm not a chemist but believe it is to do with the ethanol and other additives that generic brands tend to get added to up the rating and for ease of use on a seasonal basis.

('nonsense' I hear - all fuels re the same! Experience has proved otherwise for me)

Thank you

Edited by DCL on Thursday 3rd January 20:07

[VioletCat]

BertBert said:

Reading about ethanol says that the up to 5% you might/should get in regular unleaded will not make a difference to how your engine runs. It's also pretty hard to tell what's in your petrol even from the main brands. A quick Google says, for example, that Esso's high octane stuff is mostly ethanol free apart from in a few places in the UK! Go figure.

Re the question, I can't see why a duranail in a caterham would be worried about ethanol at the 5% level.

Bert

Thank you

[VioletCat]

MK3 Dan said:

Is the 99 stuff from Tesco?

That has a high ethanol content and I am sure they used to advertise that. We cannot get on with it in some bike engine'd stuff.

We stick with Shell/BP.

Yes it is Tesco

[VioletCat]

So I have since spoken with service at Caterham South.
They claim it could be the Cam in the Duratec engine and is typical in 420’s at this time of year. So basically I shouldn’t be driving it in the cold as the Cam doesn’t like it.
However it doesn’t matter how long I drive it for or even if I get it fully up to temperature it still behaves the same.
It’s booked in soon to have this issue and a number of others investigated I will keep you updated on the outcome.

[VioletCat]

It’s back and behaving slightly better but waiting for this tank to run dry so I can run V Power or Ultimate and test the ethanol theory.

[VioletCat]

Full tank of V Power and the rough idling and low rev grumbles have gone.
No more Momentum for me.
Thank you to everyone for the advice.