Running D5 hard

[Gazdkw]

Originally Posted by krzemien

In my case:

I only ever use Premium Diesel at all times (Shell and Total / Aral when in continental Europe) - unless unavailable / unexpected refill.
My all-time fuel consumption in my signature below. It's been variable depending on our circumstances, however in the last 8 months I started regular bi-weekly commute (so make 1,000 miles a month). In the last couple of years it was only local driving - so more like 1,000 miles in a year except when holidaying on the continent somewhere.
I do not drive it hard, I think - as evidenced by rear pads wearing faster than front ones - and cannot really remember when exceeded 3,000 rpms, might be incidental in the first year of my ownership when I forgot to change the gearbox from manual to auto! But do not drive it exactly slow either...
Engine, exhaust & emissions were commended as exceptionally clean in the past during MOT/Servicing and as I know remain as such.

OK. So, if carbon has built up and then the car is driven hard for a number of months/years etc, does it clear up?

[krzemien]

That I wouldn't know, but it suffices to say that I've made just about 1,000 miles in one year (Jul 2022 - Jul 2023 to be precise), and then ca. 7,000 miles since then - and everything works like a clockwork, and AFAIK remains clean.

I probably should have mentioned that oil level remains unchanged between services (these are done by VOLVO dealers on an annual basis).

[100K+]

2015MY V70 D5 manual.80k miles mine from new. Always add millers diesel additive. Rarely exceed 2500rpm, a bit miss Daisy driver. Driving A1 from scotch corner to newark @65mph i get 55 mpg. This is regularly replicated as I visit my daughter/grand kids.
Cheers Bob

[Kev0607]

Originally Posted by Gazdkw

Its a mix. I'd say 70% is town and 30% motorway/Dual carriageway etc.

If I reset the mpg and then drive on the motorway it's around 38-40mpg, depending how I'm driving.

Originally Posted by Gazdkw

OK. So, if carbon has built up and then the car is driven hard for a number of months/years etc, does it clear up?

30mpg mixed driving seems about right on a euro 4 XC70... Its a heavy car with an older engine. If you want better fuel efficiency, you aren't going to get that out of a euro 4 diesel. You'd have to have a euro 5 or 6. The XC70 has never been a particularly economical car. They have lots of space, are good at what they do, but fuel efficiency isn't the best compared to other estates. Volvo quote 34mpg combined driving, but real world, you can knock a bit off that because we know manufacturer mpg figures are always over inflated.

With regards to carbon, you can't stop it building up. No matter what you do, it'll always return (especially in a diesel engine). All you can do is keep it serviced, change the fuel filter and bring it on motorway trips to keep the DPF happy.

However, you can clean things like the EGR valve. Soot/carbon builds up in there, but be under no illusion, it will come back.

[Yorkshiremadmick]

My XC70 D5 SE Sport AWD has just had polestar added on the Lloyds of Carlisle
Deal. Acceleration is vastly improved as is its pulling power. The fuel consumption has also seen an improvement. Yet to calculate what it really is.