2002 W203 220CDI Fuel consumption problem

[dchantry]

Hi guys,
Still having a few issues with my car
I had poor acceleration problems which were discussed in a previous thread that ended up going to the stealership for new injectors which made my pocket considerably (£1200) lighter.
Dealers told me that the car had also been in a bump.

Since the injectors were changed the car runs a lot better, but the fuel consumption figures seem to be quite poor.
I'm getting about 40MPG from the car and 75% of my driving is motorway and I do drive more like miss daisy than Jenson Button.
I think I'm getting about 30 around town and 45 on the motorway.
I reset the computer on motorway today and then drove home at an average speed of 60MPH. Fuel consumption figures were 47. I went in a similar car last week and they had 58 doing the same.
Last week I tried filling up, driving until the tank was almost empty and then filling up again and I worked out about 39mpg. This is the same as my father in laws 2007 E220CDI
To a tank I'm lucky to get 500 miles.

Any ideas out there what figures I should be getting and if there is anything obvious to check before I go back and pay another £100 per hour at the stealership

 

[ROBB]

Hi dc,
I generally get around 500 miles to a tank over a fortnight, averaging out usually appprox 40-45 mpg over the period.
If i am v.careful driving to/from work i can get the mpg upto 55 but get bored v.easily and boot it. having said that i need to drive like a tw@ to get it below 40....
45 on the m-way does seem low - some one will be along soon with technical help

rob

 

[dchantry]

Thanks Robb

 

[Dieselman]

I'd say that sounds about normal for a C220 Auto. I've had C200 AUtos down into the low 30s but the 220 is better.

Maybe you are driving it too gently. Find some good steep hills and give it a really good workout to burn off any bore glaze. Your engine might be suffering blowby.

If there is no excessive smoke then there is probably not much to do, ypou could have the injection timing and dwell checked, and the EGR valve, but I don't think they will achieve much.

 

[dchantry]

Thanks Dieselman.
I did think it's a little low as a friend has the same car and get's such good motorway mpg, compared to me.
I'll try booting it.

 

[ROBB]

Thinking of ur low mpg, i drove home this eve rather vigourously (for a 60 zone) & when i got home mpg was 49.6.

The aircon will drain juice as well, try turning it off..

let us know what happens

rob

 

[Rory]

I did think it's a little low as a friend has the same car and get's such good motorway mpg, compared to me.

Different cars of the same model do vary though - I have C270Cdi which does 45 in reasonably normal motorway driving, but will do 50 if I try *very* hard. Yet others have posted pictures of their trip computers showing high 50's - which I've found unachieveable.

Apart from the technical details of the engine tuning mentioned earlier, I could only suggest to check the obvious things like tyre pressures, tracking etc. Also make sure that the car rolls reasonably freely (nothing binding).

 

[dchantry]

2 things.
Anyone know of a good engine tune up place in the south west or south wales. I'll get it checked out there.

2nd, the wheels on my car are off a CLK. They are Wheels Front (225 45 R17 Continental) (Rear 245 40 ZR17 Michelin Pilot Sport). My recommended presures for standard 16 inch wheels is 30 and 30. Anyone know what they should be given different wheel sizes.

 

[Dieselman]

Go to a Bosch Diesel specialist.

The tyre pressures should be fine as the weight of the car hasn't altered.

 

[fuzzer]

Different cars of the same model do vary though - I have C270Cdi which does 45 in reasonably normal motorway driving, but will do 50 if I try *very* hard. Yet others have posted pictures of their trip computers showing high 50's - which I've found unachieveable.

Apart from the technical details of the engine tuning mentioned earlier, I could only suggest to check the obvious things like tyre pressures, tracking etc. Also make sure that the car rolls reasonably freely (nothing binding).

try harder mine would easilly go up to 60 in the 270

I drove to inverness from glasgow which is all uphill and overtaking and did it in about 2:15 which is quick and i averaged 54mpg.

 

[garystu1965]

try harder mine would easilly go up to 60 in the 270

I drove to inverness from glasgow which is all uphill and overtaking and did it in about 2:15 which is quick and i averaged 54mpg.

My C270 averages about 35mpg on a 17 mile run to work, 8 miles motorway, 5 miles dual carriageway and 4 miles A road.

On a motorway run from Manchester to London I will get about 44mpg.

On a recent trip to Paris and back (1000 miles) I averaged 43mpg.

 

[merc07]

Think yourself lucky. On SLOW - 60mph clear motorway, the most I get is 39-40. As soon as I get off the motorway even for just a couple of miles it drops, then never recovers above 34/35. The dealer says this is normal for a new car? CDI 220 sport. It also pulls to the left quite bad, have had the tracking set but no change. Is this common? curious as Rory mentioned tracking for poor mpg.

Adam

 

[garystu1965]

Think yourself lucky. On SLOW - 60mph clear motorway, the most I get is 39-40. As soon as I get off the motorway it drops, then never recovers above 34/35. The dealer says this is normal for a new car? CDI 220 sport. It also pulls to the left quite bad, have had the tracking set but no change. Is this common?

With regards the pulling to the left problem trust me you will get used to it. It is a very camber sensitive car. On reverse camber road it would pull to the right. I struggled with this for a few weeks and I never even notice it now.
On a flat road it will not pull to the left.

 

[fuzzer]

My C270 averages about 35mpg on a 17 mile run to work, 8 miles motorway, 5 miles dual carriageway and 4 miles A road.

On a motorway run from Manchester to London I will get about 44mpg.

On a recent trip to Paris and back (1000 miles) I averaged 43mpg.

ok , maybe mine was fitted with a super dooper engine then :S Was it better before you had your injectors changed?

 

[Parrot of Doom]

Bear in mind that very wet roads can reduce mpg. There are a lot of rainy roads around right now. I've been doing a lot of driving lately and with the heavy downpours of late my mpg has suffered a fair bit.

I think your tyre pressures are a little low, I've always gone for 32 front, and 33-35 rear (depending on loads).

 

[Rory]

2 things.
2nd, the wheels on my car are off a CLK. They are Wheels Front (225 45 R17 Continental) (Rear 245 40 ZR17 Michelin Pilot Sport). My recommended presures for standard 16 inch wheels is 30 and 30. Anyone know what they should be given different wheel sizes.

I'm doubtful it wouldn't make a significant difference, but it strikes me that having those width tyres wouldn't be helpful to economy.

There are low rolling resistance (green) tyres available now, and your pressures seem on the low side for motorway use. However be careful if you change them as higher rear pressures will exaggerate the natural tendency of RWD cars to wear the tyres in the centres.

I'm not sugesting that you change anything, but the combination of wide, soft compound, low pressure, tyres might in combination knock a few % off the MPG figures.

On the tracking thing, most W203's seem to drift left with camber, although there are some people who say their cars don't do it. However if the car pulls (rather than gentle drift) then you're always going to be wasting fuel trying to overcome that. But you'd be seeing odd wear on the tyres too.

 

[Rory]

try harder mine would easilly go up to 60 in the 270

I drove to inverness from glasgow which is all uphill and overtaking and did it in about 2:15 which is quick and i averaged 54mpg.

Mine's an estate so I blame that! Poorer aerodynamics and I think the final drive ratio is lower.

 

[fuzzer]

I'm doubtful it wouldn't make a significant difference, but it strikes me that having those width tyres wouldn't be helpful to economy.

There are low rolling resistance (green) tyres available now, and your pressures seem on the low side for motorway use. However be careful if you change them as higher rear pressures will exaggerate the natural tendency of RWD cars to wear the tyres in the centres.

I'm not sugesting that you change anything, but the combination of wide, soft compound, low pressure, tyres might in combination knock a few % off the MPG figures.

On the tracking thing, most W203's seem to drift left with camber, although there are some people who say their cars don't do it. However if the car pulls (rather than gentle drift) then you're always going to be wasting fuel trying to overcome that. But you'd be seeing odd wear on the tyres too.

Not to add any more weight to my special car that ran on fresh air , but i had the full sports pack on mine too with sports compound 225/45/17 and 245/40/17 tyres on it.

Maybe ive just got a light foot. I used to use the tip box a lot and the cruise a lot. When driving allong i always used to tip it up to make the engine change.

 

[Rory]

Not to add any more weight to my special car that ran on fresh air ,

In normal driving (not on motorways), I'm not ridiculous about it - I always drive in S mode for example, even though I know C produces better MPG.
But I really have tried on motorways - using cruise is actually not the best thing for fuel consumption, although it's better than most people's (including mine) ability to hold a steady speed. I try to ease off as much as possible (foot off the gas shuts it off so uses no fuel at all) and I drive at an indicated 72/73 MPH.
But it really is everything I can do to get 50MPG displayed (I've checked brim to brim and think the computer is reasonable accurate).
I get to the point where touching the gas to go up an incline will knock .1 off the MPG, but then coming an incline will put the .1 back on again.

It's quite a big thing for me, as I get paid per mile - so I see the car as a money making machine. I hate having to negate my gain by putting money into it!

 

[superhands]

My 220 cdi 2006 is only giving me 28 MPG on combined driving. I couldn't believe the STAR diagnostic reported no faults. However the garage would not give me a print out of the report. Is that normal practice? Should I accept 28 MPG?

Thank you in advance.