Fuel

**IPS** · Monday 21st February 2005, 17:30

I have a T5 C70-98. Beautiful car, but using too much fuel. I had the car at the dealer twice but they say it is nothing wrong. I only get 20 miles to the gall (UK) driving with an “egg” under the pedal. It will be better on a long run ca 28 but still too much. I have ordered a new air flow meter and will fit tomorrow.
What do you think as the plugs are black as it is over fueled.
- The air flow meter is very sensitive at a low air flow
- Could it be the oxygen sensors
- Busted temp sensor showing cold engine all the time to the ECU

**volvotuning** · Monday 21st February 2005, 18:02

Driving a T5 gently is not actually the most economical way of driving it. The best way is to accelarate at reasonable pace in all the gears without going above 3000 rpm. This way you get to cruising speeds faster, where you use very little fuel.

If you accelerate too gently, you end up spending much longer accelerating, and hence much longer using more fuel.

Adam

**hamish** · Monday 21st February 2005, 21:46

28 MPG !!! Are you a 'Vicar' ?

My own T5 runs fine and the only way I can get it to do 28 MPG (and that's the best anyone's ever seen) is to lend it to my Wife ! On a run it returns between 22 and 23 mpg. On the daily run around 21 to 22 mpg. The last time I tried driving slowly enough to return 27 mpg I slipped into a Coma ! But everytime Natalie 'borrows' it the fuel computer shows 28 point something ! (at least I know she's being careful !!) I think you have just spent money unnecessarily on a MAF sensor, when you should be saving up for a Volvo D5 !

Regards,
Hamish.

**glock19** · Monday 21st February 2005, 23:55

I'm getting 14litres/100km = 3gall/62 miles = 20.7 miles/gall (imperial)
Sport mode all the way (in traffic too). Daily driving distances = 20km (12 miles)
Long distance = 8litres/100km = 1.76gall/62 miles = 35 mile/gall (avg speed = 110km/h = 68 mph)
Car = Basic 855-T5

In your case, if the temp sensor is showing cold all the time, it'll definitely run rich, as in the mornings. Changing it would help to prevent your plugs from fouling. Check also your air filter and catalytic converter for blockages if you're still in doubt over the fuel consumption.

Adam is also right about bringing the car up to speed as to let the troque converter lock up in the higher gears ASAP. The torque of the T5 should provide you a smooth cruise even at low speed in the final gear.

**IPS** · Tuesday 22nd February 2005, 07:05

I checked yesterday just driving carefully around town and the return was only 17 m/gal. I have had V8’s and other high performance cars but never seen anything like this. As you clearly state, when the engine is carefully driven it is a naturally aspirated engine with low compression ratio before the turbo boost kicks in. Fuel consumption is in a way proportional to the compression ratio. Something is definitely wrong, the metering of the MAF is very sensitive at low airflow and with reference to a Volvo mechanic I called in Sweden it is likely to be the MAF or the oxygen sensors that could still be within the “envelope” without triggering a code.
Comments pls.

**Murphy** · Tuesday 22nd February 2005, 09:01

Just to make you all feel better, i have been driving my mums 2004 4.4 V8 range rover for about 3 weeks now. The car has a range of around 250 miles and is around £70 to fill. It does anywhere between 12-15mpg, without fail. Roll on Diesel power !

**mulletboy2** · Tuesday 22nd February 2005, 09:07

I managed to average 29mpg on my last tank, sticking pretty much to the speed limit, avoiding traffic, and doing very little around town driving. I find that accelerating slowly, keeping the revs below 2500 I can usually keep the mpg consistent with whatever it was at prior to slowing down, whereas if I accelerate harder to get up to cruising speed, the mpg enevitably drops, and can take a fair while to reclaim that extra 0.1 or 0.2 mpg.

Yes, I guess I've been a bit of an anorak, but my god is it funny watching my dad's face when he realises I'm getting better mpg in a 10 year old 2.3 turbo than his brand new focus! Also, miles are tax deductable for me at the moment, so the more money I can save here, the more money I'm making at work..

[edit] Hasmish - if Natalie is doing 28mpg in and around Bromsgrove that's VERY impressive! Every time I drive around town my economy drops a lot.

**Mrsmopp** · Tuesday 22nd February 2005, 10:03

Originally Posted by hamish

28 MPG !!! Are you a 'Vicar' ?

My own T5 runs fine and the only way I can get it to do 28 MPG (and that's the best anyone's ever seen) is to lend it to my Wife ! On a run it returns between 22 and 23 mpg. On the daily run around 21 to 22 mpg. The last time I tried driving slowly enough to return 27 mpg I slipped into a Coma ! But everytime Natalie 'borrows' it the fuel computer shows 28 point something ! (at least I know she's being careful !!) I think you have just spent money unnecessarily on a MAF sensor, when you should be saving up for a Volvo D5 !

Regards,
Hamish.

Hamish I get 27.1mpg and I dont drive like a vicar!!

x

**lance** · Tuesday 22nd February 2005, 12:13

On the way up to scotland at the weekend I hit loads of traffic and averaged 27.5 mpg as soon as the roads cleared i got it down to 26.8,
Very quiet roads on the way back meant 90-120 cruising and around 25.5 mpg overall 700 odd miles.
Strangly I can sometimes get better economy dodling round town, cos when the road opens up and the engines warm i boot it!
My computers normally between 23-25 mpg

**IPS** · Tuesday 22nd February 2005, 16:27

Replaced the MAF sensor today and the reading went up to 23 from 15-17 around town. ???

**glock19** · Wednesday 23rd February 2005, 09:17

Could be. I've just checked the original press release for the T5 and they officially quote 21 mpg for city driving.

**Goof** · Wednesday 23rd February 2005, 18:34

21 sounds about right here too - my daily journey is 14 miles and it takes just under an hour. Current av mph is 24, at av 21 mpg. Gets better on faster journeys.

**JUDGENINJA** · Thursday 24th February 2005, 05:55

I agree..... I got 23-24 mpg on the run to well lane the other week...but I rarely get over 21 going to work and back..

**Martinr** · Friday 25th February 2005, 11:37

Didn't buy the car for its' fuel consumption properties.

I have been impressed by the fuel consumption of my 855 on a motorway run. Best I have seen is 31mpg That was achieved on cruise control 4 up with luggage. Set to cruise around 75 - 85 mph on a journey from Birmingham to Frimley and hardly altered speed the whole way.

Big improvement over a Discovery V8 I owned a while back, 11mpg. Drove to Ireland in it £130 of fuel in 4 days. Ouch!!

Round town it's a different story in the nose to tail stuff. Stop start most of my way to work. I now drive further just to find a place to open it up

I am becoming friends with the guy who works in the local Shell station though!

Consumption seems to have improved since switching to Optimax but this coincided with a major service so can't say if that is down to the fuel or the new plugs, filters etc. Will check as things settle down.

**Justin** · Friday 25th February 2005, 11:45

Well said, if i wanted 45 to the gallon i would not be driving a T5.

**Goof** · Friday 25th February 2005, 17:27

The handbook suggests changing gears thus:-
into 2nd at 20mph, into 3rd at 30mph, into 4th at 40mph, into 5th at 50mph ~ which works at at between 1800rpm to 2600rpm (roughly). Doing this does seem to improve mpg somwhat, but nailing it when you join the motorway seems to nullify all previous efforts!

**siamblue** · Saturday 26th February 2005, 12:05

Buying a T5 you don't do it for economy,I came back from Southampton the other day,and did half a tank in 120 miles,I wasn't hanging around lol,
But taking it easy i can get 30 mpg out of her.

**Mickey** · Thursday 10th March 2005, 01:52

aha, but there is an answer

I thought I was going to have to sell my baby when the kids moved school, and the daily run became 50 mile.

There had to be a solution, feed the beast GAS I thought, so I did, now the wife gets to take the kids in comfort and I get my baby at weekends.

Performance is hardly affected, and its only a switch to change back to good ol 4 star should the devil in me raise its ugly head

I get about 220 ish miles on 20 quids worth of gas, so ecenomical runabout she is.