Poor fuel consumption in W203 C220cdi

[jberks]

I drive from Orpington, to Brentford on the A4 everyday and back again, some 57 miles (one way) of mixed driving, Either the computer is incorrect or the W210 is more economical?? wierd!

I'd have to say that if you could genuinely get neartly 60mpg out of an E220cdi that would be great. But I doubt that in reality you can. It would be interesting to do a neck to neck check _ i suspect you are closer to 45mpg.
I have a friend with a new 320cdi, drives it hard and gets better mpg than I get from my 270. I suspect the real difference is in the way the computer calculates more that actual efficiency savings.

 

[Matt_EClass]

You could be right Jberks, but can the computer be that far out? I will have to try it the old fashioned way, full tank and the fill up at the end of the week and see how much Ive burned.

Regards

 

[psmart]

You could be right Jberks, but can the computer be that far out? I will have to try it the old fashioned way, full tank and the fill up at the end of the week and see how much Ive burned.

Regards

Make sure you fill until fuel almost comes out the overflow. This ensures any backpressure problem doesnt affect the test. My ML, you can get 2 gallons in after the first cutoff click.

 

[Blobcat]

You could be right Jberks, but can the computer be that far out? I will have to try it the old fashioned way, full tank and the fill up at the end of the week and see how much Ive burned.

Regards

My computer used to average ~40mpg the reality was 36.59mpg so ~3mpg out

 

[television]

My computer used to average ~40mpg the reality was 36.59mpg so ~3mpg out

I do not look at mine, I am too young to die:roll: :roll: :roll:

 

[psmart]

My computer used to average ~40mpg the reality was 36.59mpg so ~3mpg out

It will probably be a factor of age/mileage. Given that the ECU is accurately injecting a given quantity of fuel, less tolerances ot items such as bar pressure sensor, injector response/wear, as a car ages, it will probably become less and less accurate.

 

[Blobcat]

It will probably be a factor of age/mileage. Given that the ECU is accurately injecting a given quantity of fuel, less tolerances ot items such as bar pressure sensor, injector response/wear, as a car ages, it will probably become less and less accurate.

As the difference stayed the same for ~110,000 miles that theory has just crashed and burned :lol:

 

[psmart]

As the difference stayed the same for ~110,000 miles that theory has just crashed and burned :lol:

Strange that... as you would expect differences in the very least when the tyre tread depth altered. Perhaps Merc employ Fuzzy Logic to guestimate mpg.

 

[OmniCognateNeutronRangler]

I know this is going back a bit but I have been tooling around in a 55 plate C220CDi Avantgarde for the last 3 days and I must say that on average I only got around 5 to 7mpg better than my C240 and I drove the C220 quite sensibly too. The best I got out of it was about 38mpg on the work run and about 32mpg on my C240. Thoroughly un-impressive IMO. Certainly not worth the transit van sound effects for (which are very obvious under about 25mpg).

 

[pomm001]

31 from a C220 does sound poor. Trickling along urban roads in my E270 I can see 30-32. Admittedly throw in a few hills and hold ups and I can also see 23 but on the other side, I regularly see 41+ on a motorway at 75-95 and I once got 48 but that was driving like a pensioner. (and I have silly wide tyres which can't help).
The problem is that so many factors affect it, from driving style to hills and traffic and even the weather.
The best I got from my E240 was 37 (once, driving the same way my 270 gave me 48 ), it would do 33 on a run normally but I also saw 13 a fair few times!!

All I can suggest is to view it logically. The fuel has to go somewhere. Assuming the car is performing ok, then it's either dropping it on the road (should be visible), throwing it, unburned, down the exhaust (black clouds under acceleration) or needing too much in the first place (under inflated tyres, tugging a trailer, binding brakes etc).

My 04 W211 220 returns on average 38 mpg mixed driving measured in the old fashioned , tank to tank method , on a steady 150 mile motorway trip can see mid 40's .
Read out always optomistic as its a 'calculated' figured taken from the ECU rather than physical volume or weight of fuel consumed.
My class 1.4 averages 34 mpg doing the same run.

 

[jberks]

Work run - traffic for 6 miles each way with the odd blast to 70 where possible - computer shows 28-31
Brim to brim shows 26.
Not great for a diesel.

 

[psmart]

The key to economy is zoom... zoom... brake... zoom...

NOT!

Being a boy racer in years gone by, I do not do the zoom zoom car tango dance ... (to give it a name) ... any longer. This, along with auto-boxes and air-conditioners eat fuel.

I drive fast, way faster than just about anyone on this forum, regularly, but high speed doesnt suck fuel as much as zoom zoom! I also take my time to top speed, rather than ram down to a lower gear, zoom then brake as nerd in BMW pulls out in front of me!

Last night, on way back from Alps, 30'c, the A-Class was showing 110 on the dial, touched ~118 at one point. It was hot, very hot, so I switched on the aircon.... what happened... top speed down to just a tad over 100!

Driving style is really what its all about (given the car is in full working order).... you could say that mpg is a Boy Racer barometer

Just to add, the A-Class is a 140 petrol, and Ive noticed that Octane has a BIG impact on mpg. Best MPG is returned on 91 Octane, then 100 Octane and 95 Octane returns crap MPG.

 

[Blobcat]

NOT!

Being a boy racer in years gone by, I do not do the zoom zoom car tango dance ... (to give it a name) ... any longer. This, along with auto-boxes and air-conditioners eat fuel.

I drive fast, way faster than just about anyone on this forum, regularly, but high speed doesnt suck fuel as much as zoom zoom! I also take my time to top speed, rather than ram down to a lower gear, zoom then brake as nerd in BMW pulls out in front of me!

Last night, on way back from Alps, 30'c, the A-Class was showing 110 on the dial, touched ~118 at one point. It was hot, very hot, so I switched on the aircon.... what happened... top speed down to just a tad over 100!

Driving style is really what its all about (given the car is in full working order).... you could say that mpg is a Boy Racer barometer

Just to add, the A-Class is a 140 petrol, and Ive noticed that Octane has a BIG impact on mpg. Best MPG is returned on 91 Octane, then 100 Octane and 95 Octane returns crap MPG.

You had the AC on! your not ill are you :roll:

 

[psmart]

You had the AC on! your not ill are you :roll:

.... arent passengers annoying

 

[Blobcat]

.... arent passengers annoying

Now I know the reason you had the AC on I feel better. I was worried about you there for a nano second. I half expected you to start speaking in tongues

 

[psmart]

... I half expected you to start speaking in tongues

Couldnt get away with that.... my passenger speaks French, German, Italian, Spanish, English and 2 M.E. languages!!! :Oops: