Coking up

[BigAl]

As mine had to go back in last Friday to have a new battery fitted, I let them keep the car all day to do a comparison on the engine sensors. This came about when I mentioned that I'd run mine from new on Shell Vpower fuel. They had been recommending customers to switch to this based on Mazda advice over the ongoing coking issue.

The outcome was interesting. Mine is coking up, but nowhere near as much as some they have seen with lower mileage. Certainly doesn't need dealing with as yet. Conclusion they came to is:-

• V power or other premium fuel is best
• branded fuel is OK
• avoid supermarket diesel if at all possible

Reason for the last is that supermarket diesel can aparrently be diluted up to 30% with bio-diesel! That's one of the reasons coking up is occurring. The mentioned that Mazda Japan are working on a software update for this but it's taking time. Dealer says he's hoping that the extra space in the fuel filler on the new model is for Adblue as he reckons it would solve the problem. Symptoms of coking up show up as hesitancy or stuttering on acceleration.

Alan

[Deeps]

Interesting, Alan, especially the mention of Supermarket diesel being 30% diluted with bio-diesel. I've not had cause to fill up recently but somewhere in the distant fog I feel sure that I've read on the pump itself that the normal Shell fuel is partly bio. Must have a look at the pump when walking past later today.

[BigAl]

I've not been able to verify that mix independently, it's something the dealer mentioned to me. As I was already using Vpower anyway, and probably reaping the benefits, it was no hardship to me!

Alan