Very poor mpg at 21.5 mpg - Page 2

nbuuifx · Dec 15th, 2012, 22:33

Could be a whole host of things. I doubt different fuel/ fuel additive would have any effect.

Does it feel like it is running OK? Have you checked properly how many miles you are doing for how many litres? Don't just rely on the onboard computer as it may have gone tits up.

What is the service history like? Has it been serviced regularly? If so the fuel filter should have been done so shouldn't be a problem (you would notice a problem with it running before it gave bad mpg)

I've always found mine to be low, but I do terrible journeys - all short and up and down hills, but I still get 35ish.

Try and borrow aN OBDII reader or get the codes read at a garage, it may tell you straight off what is wrong.

Zeb246 · Dec 16th, 2012, 00:18

Quote:

Originally Posted by nbuuifx

Could be a whole host of things. I doubt different fuel/ fuel additive would have any effect.

Does it feel like it is running OK? Have you checked properly how many miles you are doing for how many litres? Don't just rely on the onboard computer as it may have gone tits up.

What is the service history like? Has it been serviced regularly? If so the fuel filter should have been done so shouldn't be a problem (you would notice a problem with it running before it gave bad mpg)

I've always found mine to be low, but I do terrible journeys - all short and up and down hills, but I still get 35ish.

Try and borrow aN OBDII reader or get the codes read at a garage, it may tell you straight off what is wrong.

Hhhmmm...Was hoping that this could solve the problem. The car is running fine, I haven't checked how many miles i'm doing on fuel, will make sure i will check before and after on miles. The car has been serviced by Volvo, then been serviced at a local garage, inc cambelt change. Service was done 2 weeks ago. The previous owner did all the work. I might give MRG a call and let them do the free health check.

colinjy · Dec 19th, 2012, 11:21

tyre pressures ok ? it shouldn't drop it that much but if there quite low then you'll notice a drop

rowdy · Dec 19th, 2012, 16:52

Age and mileage of car?

DPF could be clogged, any warning messages on dash at all?

I find my mpg drops this time of year, due mainly to use of seat heaters, window/mirror demisters, leaving car running to de ice in morning, apparently diesel in winter is a different mix etc, but 21mpg is terrible, something is wrong!

Zeb246 · Dec 19th, 2012, 17:27

I will check the tyres and pump them up. Could it be down to wrong tyre fitments? Front tyres are 225/45/18 and rear tyres are 225/40/18. Mileage on car is 44K miles, 2007 plate.

It's a gear tronic, don't know if the auto gearbox reduces mpg?

ian7675 · Dec 19th, 2012, 22:08

Just as a comparison, my T5 is averaging between 30 and 35 mpg and the turbo does get worked quite regularly so I'm amazed yours is that low. 21 to 25 mpg is really bad for a diesel car. Sorry for not actually helping you with your problem.

Edit: mine is also gear tronic, it will fractionally reduce your mpg.

Zeb246 · Dec 19th, 2012, 22:53

Out of a diesel that is very bad, at most I will get 25.8mpg on the motorway. Still bloody low, so tomorrow I am going to add Millers additive and a full tank of Shell diesel, then take it on the motorway and see if the mpg goes up.

Everything is absolutely fine on the car, engine and gearbox are fine, and no messages on the dash.

sprout99 · Dec 20th, 2012, 08:11

Quote:

Originally Posted by Zeb246

Out of a diesel that is very bad, at most I will get 25.8mpg on the motorway. Still bloody low, so tomorrow I am going to add Millers additive and a full tank of Shell diesel, then take it on the motorway and see if the mpg goes up.

Everything is absolutely fine on the car, engine and gearbox are fine, and no messages on the dash.

Change air and fuel filter anyway.

The Auto's are known for being thirsty as they rev harder.

Ours does 40mpg (Manual) and thats mixed driving with lots making it work for the love of the 5 pot growl.

Ours has done 137K so defo run in and never uses a drop of oil.

Bendolfc · Dec 20th, 2012, 10:29

Possibly an example of why low milage diesels aren't always a good thing, has it pootled round town all its live and never been stretched? Get it fully upto temp and give it a good high revs blast.

sprout99 · Dec 20th, 2012, 10:38

Quote:

Originally Posted by Bendolfc

Possibly an example of why low milage diesels aren't always a good thing, has it pootled round town all its live and never been stretched? Get it fully upto temp and give it a good high revs blast.

i had a 4 year old Octavia vRS TDi a while back that had only done 26k
but never been serviced properly and used in frequently and short runs

it wasn't a good car and I sold it

Dec 19th, 2012, 22:08	#16
ian7675 Senior Member Last Online: Aug 25th, 2013 21:53 Join Date: Aug 2012 Location: Gloucester	Just as a comparison, my T5 is averaging between 30 and 35 mpg and the turbo does get worked quite regularly so I'm amazed yours is that low. 21 to 25 mpg is really bad for a diesel car. Sorry for not actually helping you with your problem. Edit: mine is also gear tronic, it will fractionally reduce your mpg. Last edited by ian7675; Dec 19th, 2012 at 22:10.

Dec 15th, 2012, 22:33	#11
nbuuifx Senior Member Last Online: May 1st, 2015 23:01 Join Date: Dec 2011 Location: Staffs	Could be a whole host of things. I doubt different fuel/ fuel additive would have any effect. Does it feel like it is running OK? Have you checked properly how many miles you are doing for how many litres? Don't just rely on the onboard computer as it may have gone tits up. What is the service history like? Has it been serviced regularly? If so the fuel filter should have been done so shouldn't be a problem (you would notice a problem with it running before it gave bad mpg) I've always found mine to be low, but I do terrible journeys - all short and up and down hills, but I still get 35ish. Try and borrow aN OBDII reader or get the codes read at a garage, it may tell you straight off what is wrong.

Dec 19th, 2012, 11:21	#13
colinjy Junior Member Last Online: Jun 4th, 2016 01:31 Join Date: Sep 2012 Location: Oxfordshire	tyre pressures ok ? it shouldn't drop it that much but if there quite low then you'll notice a drop

Dec 19th, 2012, 16:52	#14
rowdy Senior Member Last Online: Jan 10th, 2024 06:10 Join Date: Jan 2010 Location: West Sussex	Age and mileage of car? DPF could be clogged, any warning messages on dash at all? I find my mpg drops this time of year, due mainly to use of seat heaters, window/mirror demisters, leaving car running to de ice in morning, apparently diesel in winter is a different mix etc, but 21mpg is terrible, something is wrong!

Dec 19th, 2012, 17:27	#15
Zeb246 Senior Member Last Online: Jun 9th, 2013 13:19 Join Date: Jul 2012 Location: Bristol	I will check the tyres and pump them up. Could it be down to wrong tyre fitments? Front tyres are 225/45/18 and rear tyres are 225/40/18. Mileage on car is 44K miles, 2007 plate. It's a gear tronic, don't know if the auto gearbox reduces mpg?

Dec 19th, 2012, 22:53	#17
Zeb246 Senior Member Last Online: Jun 9th, 2013 13:19 Join Date: Jul 2012 Location: Bristol	Out of a diesel that is very bad, at most I will get 25.8mpg on the motorway. Still bloody low, so tomorrow I am going to add Millers additive and a full tank of Shell diesel, then take it on the motorway and see if the mpg goes up. Everything is absolutely fine on the car, engine and gearbox are fine, and no messages on the dash.

Dec 20th, 2012, 10:29	#19
Bendolfc Premier Member Last Online: Yesterday 14:20 Join Date: May 2010 Location: Liverpool	Possibly an example of why low milage diesels aren't always a good thing, has it pootled round town all its live and never been stretched? Get it fully upto temp and give it a good high revs blast.

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