MPG issue

Hi all.

I have just done the calculation to see what my range rover 2.5DT mpg was.

been told its supposed to be about 20-21.

im doing 13mpg.

no wonder why im doing 30 miles off a tenner.


what i wanna no is whats the best things to change on the car to try and get the mpg as close as possible to what its supposed to be.
i no the oil needs a change, been meening to do that for months but thats still on my endless to do list.

what could be causing it.

13 mpg that's worse than my V8! you sure you're not driving with one foot on the brakes?

lol, defo. i have actually checked all the wheels, jacked it all up and spun wheels to check the brakes aint sticking but no problems found. handbrake on and off. all ok.

off road tyres can seriously knacker mpg averages, what's your driving style like? is it all short runs? loads of other things can affect it but defo get a good service done asap.

The in tank pump failing seems to cause low mpg, as do knackered leak off pipes, otherwise check your airfilter. Might be worth checking fault codes.
I get 23/24mpg on local use and up to 30mpg on the autoroute cruising at 130kmh

Clean out intercooler, fit a new air filter, have the injectors serviced. Don't drive like Lewis Hamilton. All of those could improve you MPG. How old is it, is it a high miler? Driving in heavy traffic stop/start will seriously affect your MPG.

i recently changed the fuel filter becuase mum put petrol in it. but miles have not changed. same as before.
it does blow black smoke, but only when pushed to very high revs.

how much to get new injectors, or refurbs???

also i could do with a new fuel pump, not very acurate whith the deisel dial on dash.

mikey!!!! said:

i recently changed the fuel filter becuase mum put petrol in it. but miles have not changed. same as before.
it does blow black smoke, but only when pushed to very high revs.

how much to get new injectors, or refurbs???

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Diesel Bob will refurb your injectors for £28.00 each plus Vat. Works out at £197.40. But you will have to take them out and send them to him, he does not do exchange units, about three days turn round i think.

thats pretty good. ok i might have to. how do i get hold of him.

Also i never worked on an intercooler. dont really know what it does. could it be blocked.

i was thinking of selling the car becasue i also have to get a new steering box, but i will pay for that if i can figure the mpg problem out. spending so much money on the deisel. supposed to be cheaper than petrol. not mine.

mikey!!!! said:

thats pretty good. ok i might have to. how do i get hold of him.

Also i never worked on an intercooler. dont really know what it does. could it be blocked.

i was thinking of selling the car becasue i also have to get a new steering box, but i will pay for that if i can figure the mpg problem out. spending so much money on the deisel. supposed to be cheaper than petrol. not mine.

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Do a search. 'Diesel Bob tuning'.

Just take intercooler out and flush it a few times with a good solvent.

The turbo gets very hot, air gets hot as it is compressed, hot air is thin air, thin air needs less fuel by volume to maintain correct mixture ratio, so gives less power. The intercooler cools the air charge to make it more dense. Denser cooler air can accomodate more fuel so gives more power. Simples.

wammers said:

Do a search. 'Diesel Bob tuning'.

Just take intercooler out and flush it a few times with a good solvent.

The turbo gets very hot, air gets hot as it is compressed, hot air is thin air, thin air needs less fuel by volume to maintain correct mixture ratio, so gives less power. The intercooler cools the air charge to make it more dense. Denser cooler air can accomodate more fuel so gives more power. Simples.

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oh right, its that simple then, lol. coolio.

i'll get onto it at weekend. any other ideas for what the mystery low milage could be caused by??

barmatt said:

13 mpg that's worse than my V8! you sure you're not driving with one foot on the brakes?

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The worst I've ever had with the 4.0 is 11 mpg :doh: That was last week after a full service but due to a lot of short trips in terrible terrible traffic (1.5 hours to go 5 km) with ac on full. This week completely the opposite; 22mpg. This also happens to be the best I've ever had and due to a series of 20 mi to-and-fro journeys at about 40 - 50 mph on a fairly deserted road. My long term average over the time I've owned the car is about 16 which is lowish but its because of driving conditions and fuel quality.

Hi Mikey!!!!
I know that everyone will moan when i say this....where do you fill up?? i get 13MPG from jet up to 22MPG from shell. i think there is a huge difference between fuel stations and suppiers.

P.s just changed my air filter and it's made a difference

usually fill up at the total garage over the road.

air filter also looks fine. still looks new. no crap in it.
had new fuel filter last month.
defo needs new oil and new oil cooler pipe. but cant see how that would affect it.

I have to agree on the fuel. Jet or any other cheap fuel, gives poor MPG for my DSE. Normal shell far better MPG. I am getting 20 around town with stop start driving and 30 if over a 5 mile trip. Have you tried the Millers Diesel addative from Halfords?

dean68uk said:

I have to agree on the fuel. Jet or any other cheap fuel, gives poor MPG for my DSE. Normal shell far better MPG. I am getting 20 around town with stop start driving and 30 if over a 5 mile trip. Have you tried the Millers Diesel addative from Halfords?

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no i havent. any good???

so i take it shell is the better station to use????

gotta think where there is one around here.

put a tenner in yesterday at shell.

normally i would get about 37 miles from £10. but its done 35 already and only used about £6-7.

defo using shell from now on. thanks for the tip ladyranger!!!!

i no the feeling, i get 13-15mpg around town drivin nice, and 17mpg on the motoway doing a constant 60mph...

Mike

what ya driving .. 17MPG @ 60 .. not good, i get 23-24 mpg in a 4.4hse... fully laden!