Driving style?
 

Since having to use a lot of 30mph roads atm, I’ve noticed if I travel at 30 in 3rd gear at around 1600rpm I get better mpg rather than 1300rpm in 4th.

What gear do you use when your doing 30mph?

I’ve noticed a lot of smoke pulling away in 1st gear too... nothing in any other gear too?

I discovered 60mph in 5th is more economical than in 6th. 1800rpm rather than 1500rpm.

The smoke is only noticeable on yours when pulling away because once you're moving the smoke is dissipated more so you don't notice it.

When in the likes of 3rd gear and high revs there is no smoke I can see from the person behind me headlight. It’s only like when the car is pulling away it revs itself up a little and that’s when you see the smoke.


I’ve also noticed at 50/60mpg I use 5th gear too. I used to go straight up to 6th but holding off now. Higher revs tend to return better mpg

If you're sure, but I think I'm probably right! :speechless-smiley-5

Either way, I'd suspect valve guides/oil seals, or turbo seals. It won't be doing your DPF any good either.

You could try a different viscosity engine oil (assuming you've not been running on rubbish oil) and see if that helps.

Tonight car was doing a regen on motorway then came off and was smokey. Parked up at a family members for about 40 mins and when I left I decided to drive a little hard.... there was no visible smoke. Held revs higher than usual and pulled away and no smoke. My oil level hasn’t changed and coolant level is still full. Not sure if 1 injector is sticky or spray pattern is messed up.
Always used shell or petronas 5/30 and used triple qx but done more oil changes as I got a deal on 20l.

I seem to remember that many, many years ago I read that an engine is at its most efficient when delivering peak torque. I also read that many oil fuelled ships delivered the best balance between range & speed when turning over at revs equating to peak torque.

If you are running the car at revs closer to its peak torque output, might that explain the apparently better economy when the engine is turning over at higher revs - closer to peak torque revs??

I assumed your smoke was blueish. Is that an incorrect assumption?

Interesting..........

Grey/white smoke from what I can see. I myself think it’s a dirty injector. But obviously there is more things to cause the smoke.

Might run my fuel low - something I never do, and put a injector cleaner into it.