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Discussion Starter #1
hi all i have a 2002 90 hdi 2ltr,owning it now for 3 months,my mpg wont go above 34.9 and thats driving like a grandad..
i often service it and treat it with wynns egr and fuel cleaner,ive had it plugged in and no faults coming up....i went on a 200mile motorway hike and it did manage 36.5 ,thats sticking to around 60 - 70 mph...

why is my mpg so low....help...:mad:
 
J

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Is that the trip computer reading, or a manual calc?

If its the trip, maybe worth trying again with a manual calc just to check the trip is working correctly.
 
J

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Hey, please can someone explain how to work out the MPG yourself?
Reset the mileage trip, and fill the car up with fuel.
Drive until down the 1/4 tank or so.
Refil the tank again, noting how many litres you put in.
Make a note of how many miles you've driven in that time.
Then calculate mpg using: (miles / litres) * 4.54

Then you're done :thumb:

Its basically what the trip is doing, but just a manual check. I've checked mine before, and trip was within 0.5mpg of the manual calc, so shows its working OK.
 

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i also find your MPG will go down if you have lost pressure in your leak back pipes on your injector, also you loose alot of fuel...

for a while ive been running on around 37mpg for a while, changed the leakback pipes and replaced the clips its gone up to 60mpg! must of been a blockage or pressure loss...that finally made the pipe blow off and dump fuel in the engine bay and drip onto the roads. class when i took it to work and the fitters called all the buses in to check all of them for a diesel leak test...never told them it was my car :lol:
 

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The distance between each mark on the fuel gauge is 7.5 litres or 1.65 gallons. If you get 99 miles between each mark you are getting 60 mpg.

This is quite hard to achieve, but it can be done. You use something like 10% more fuel travelling at 70 as opposed to 60 - something like that anyway, its a HUGE difference in consumption for relatively little speed gain.

Its not just speed as well, remember to change up before 2k rev's, to accelerate gently and to take your foot off the accelerator to slow down when approaching a junction as opposed to slamming on the brakes.
 

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You'd be able to smell any diesel that was leaking - have a look under the engine to see if there is any diesel there.
 

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yeah you will see fuel if they were leaking and smell it loads in the car. what i meant in saying that, is a blockage in the pipes could also cause a drop in MPG as the fuel going back is not circulating (being eco).
 

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Discussion Starter #13
hope the egr is not faulty as i cant afford that to be replaced(engine out job)

i,ll take leak off pipes off and blow them out..
 

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for your egr, might be worth buying wynns egr 3 from ebay and using that to give it a good clean :thumb:
 

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Discussion Starter #16
finally managed to use the full tank of derv,filled from light coming on and managed 563 miles to a tank and thats all short stop start journeys....

think thats pretty good..:thumb:

my computer is still reading 34 mpg so i know now its reading wrong...
 
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