on a run 35mpg from a cdti is shocking. i can get 38 from my zt 190. my cdti mgzt does 38 around town. and over 50 on a run. something not quite right there. overfuelling maf/boost leak?. etc.

 

Yes that's not the best mpg..I would hope for better.
Pete

 

A good test for consumption is to reset the obd display while cruising at 60mph on the flat in top gear. If all is well you should see about 60 mpg.

 

From experience around central London i'm getting appox 30mpg in my ZTT... loads of stop start and heavy right foot though... closer to 45 on a good run though
J

 

I reckon about 35 mpg. Did 480 miles on £ 80 worth of fuel at around £ 1.42p per litre.

Reckoning is really not good enough.

Fill the tank, zero the odometer, drive it about and fill it up again. Note the mileage you have covered. Look at the litres used on your receipt, divide by 4.54 to get the gallons.

Divide the mileage driven by the gallons used and you'll actually know the mile per gallon you are getting.

Really, '£80 worth' of fuel is a pointless measure (but if your figures are correct it would have been 12.4 gallons and you would have been getting 39mpg which is a bit better than your guess, but still pretty bad. I'm getting an average of 47 mpg from my manual saloon (the tourer is reportedly less economic and the auto certainly is) have done motorway runs getting 53mpg.

 

my last two fill ups as follows41.9 litres = 34.71 mpg 320 miles 9.218 gall


50.91 litres = 31.25 mpg 11.2 gall

mostly 0 to 5 mile trips

 

my last two fill ups as follows

34.71 mpg

31.25 mpg

mostly 0 to 5 mile trips

Yikes! And that is why I use a bicycle for short trips!

 

Would expect 48-50mpg out of mine. If its a manual then something must be wrong

 

Have checked mine over the last 2 months or so and i am getting between 35 and 36.5 to the gallon this is based on fill up to fill up calculations and the on board gauge is saying 38-40 mpg
Cheers Rob

 

Fits my findings just keep fillin her up too old for a bike now last time was about 50 years ago when i was a paper boy with saturday night football final

 

Fits my findings just keep fillin her up

I'm sure!

too old for a bike now last time was about 50 years ago when i was a paper boy with saturday night football final

I'm guessing that only makes you about 60 and only 10 years older than me! You're never to old to ride a bike.

 

Thanks for all your replies. Looks like I have a problem. Will do the brim to brim test first though

 

Is your gauge 'in the middle' when the car is up to temperature? Is your cabin heater hot?

If not a tired thermostat will tend to cause you to use more fuel as diesels are more efficient when they are hot. I gained an average of nearly 4 mpg when I changed the 'stat.

There are lots of other things that can eat fuel, roof racks, tyre pressures, lots of short trips, auto boxes, a loaded car and so on.

 

I get over 40 MPG on a run in my 1.8 and 37 for my daily commute.

The 190 does about erm.. 27

To be getting 35 out of a diesel there must be something up.

 

well i must have bought two bad uns because they have both been same average except on long runs when 45 ish acheived

 

It was 180 miles one way. One third of that was motorway at 70 to 80mph. The rest of the journey was a mixture of slow windy stuff behind tractors etc and a bit of medium fast village to village stuff mainly 4th and 5th gear.

 

after reading this im a little concerned myself.

my trip computer is reading at 16.7 mpg i thought this may be buggered

but.....

from the light coming on i put 40ltr of petrol in which lasted only 160miles until the light came back on.

i figure that to be 18mpg?

that is bad surely?

why would this be? the car seems to be running very well

190+ kv6 btw

 

after reading this im a little concerned myself.

my trip computer is reading at 16.7 mpg i thought this may be buggered

but.....

from the light coming on i put 40ltr of petrol in which lasted only 160miles until the light came back on.

i figure that to be 18mpg?

No. You have no idea how much was actually in the tank when you started or finished.

It is important that when you calculate your consumption you are working off a known volume of fuel. Brim the tank, drive about, brim the tank and measure the volume of fuel against the mileage covered.

 

This is always a hot subject. In 3 years in mine I have always averaged mid to late thirties. Occasionally get around 40 on a long run. Thermostat fixed, egr cleaned, inter cooler o rings done, MAF and mafam fitted etc. no fuel leaks. I'd love to know how people get the figures they do. I'm with Ken and others on this subject.


Please insert signature here or don't the choice is yours

 

mintee you 50 me 68 too old to start riding a bike again lol
glad to see simcor s comment re fuel mpg i have done mixed trips and figures looked good like 250 miles covered and showing half a tank giving you the feeling yer gonna get 500 from a tank full then bugger you only get 450
my feeling now just keep filling up and dont worry gotta £9 rise coming april in my pension lol

OAP Somewhere near Manchester

 

pay day loan

 

at a bargain price of 1796apr :twak:

 

hi

i am sure some view the consumption guage through rose tinted specs, or they are driving Miss Daisey style.

my 1.8T does 27-28 constant, lots of around town/kids/bit of motorway.

i have a picasso 2.0 HDi constant at 36 mpg (again mixed driving)

i had a C4 1.6 hdi picasso, over 5k miles did 37 mpg.

to me normal driving in built up areas/to work/ dropping kids etc you will get the mid to latter 30's.

you will only see over 40mpg when more like 75% plus is long distance with foot stuck on one position on accelerator, thats how things are.

cant seee how anyone is getting 35 in a 1.8T with normal driving, just does not stack up. you'd struggle to get that in a 1.2 corsa.
efficiency is best with constant load/power close to 56 as possible.

i once went to the coast in a diesel metro sticking to 60 mph( very difficult!!), and reckon i got (brim/brim) about 68 mpg!!

 

i am sure some view the consumption guage through rose tinted specs, or they are driving Miss Daisey style.

No rose tinted specs here and I have a Synergy set on 10 all the time because I can use the torque.

I have filled my tank to the brim every time I fill (less time wasted at petrols stations, and I'm going to use it anyway) and I have recorded the mileage used on a spreadsheet since I got my car a couple of years ago.

Before I changed the thermostat I averaged 43.09 mpg. After I changed it I have averaged 46.95 mpg.

People will get different mileage depending on what they do, what they carry, the way they drive and so on. But to label individuals simply because they are better at driving economically than you can manage is a bit much.

 

Approx 36 mpg , is that good?

As generally noted, that's pretty poor for the diesel. Apart from servicing the usual bits and bobs like the EGR, etc, I'd suggest the prime cause is a low running temperature. You haven't mentioned the temperature gauge, but I'd guess it hovers below 9 o'clock for much of the time. Do some OBD coolant temperature checks and you'll confirm whether my guess is good or a load of hot, or maybe warmish air (like the heater?)

TC

 

TBH36 mpg is appalling out of a CDTi.

That's about as low as I got mine when I did a trip up to Motherwell last year, 400 miles at silly speeds, won't say what, but let's just say I found out at what speed the cruise control runs out and you have to push the loud pedal down to get more speed.

I achieved an average of 36 on the way up.

Coming back didn;t need to be as frenetic, so I cruised back at normal motorway speeds and achieved an average of 56.7 Mpg, so in effect caning it cost me 20MPG, which is very significant.

Even using my car as I do, which is driven pretty hard and also carrying quite an amount in the back I get 36.2 to the gallon average, which is a bit motorway and lost of round town & twisty stuff driving. Which I think is excellent MPG for the car and the driving I do.

Regards, Rob.

 

I've had my ZT CDTi 135 for 3 months now and have done 6K miles watching the consumption all the time (carefully calculated brimful method as described above). The journeys have mostly been longish (65 miles) or long (200+ miles).

Worst consumption has been 42 mpg cruising at 80 and a heavy-ish right foot from time to time. Best has been 45 mpg crusing at 70 - 75 from Pembrokeshire to Cambridgeshire.

No engine mods and not really nursing it. My mate has got a 75 D estate and he gets the same figures. So if you only get 37 there's either a problem or you're chnaging gear too late. No need to rev these engines!

BTW Sounds like the guy who started this thread has been in Wetherspoons in Llandudno - full of scantily dressed yound ladies. Disgraceful! And you won't hear any Boyo accents because they belong to South Wales which is effectively a different country (speaking as a North Walian - no offence Taffy!!).

 

I get 51.3 on the computer but I have all the engine mods.

I am very disappointed if I have to fill up having done less than 500 miles.

And I just drive it.