Is my trip computer kaput???

[peterg1965]

I drove down to North London in the CLK55 yesterday, steady driving on busy roads mostly and was driving at the prevailing speeds. The onboard trip computer ended up reading 31.7 mpg after 250 miles. I haven't yet filed it up to do the brim to brim accurate mpg, but I suspect the OBC is over reading isn't it?

If it is acually anywhere near 30mpg I will be amazed, staggered, disbelieving but very pleased - although I dodn't buy the AMG for economy!!

 

[C240Sport97]

hope this helps (from my dearly departed 208 55) .. your trip computer is not broken!

 

[st4]

I drove down to North London in the CLK55 yesterday, steady driving on busy roads mostly and was driving at the prevailing speeds. The onboard trip computer ended up reading 31.7 mpg after 250 miles. I haven't yet filed it up to do the brim to brim accurate mpg, but I suspect the OBC is over reading isn't it?

If it is acually anywhere near 30mpg I will be amazed, staggered, disbelieving but very pleased - although I dodn't buy the AMG for economy!!

Say its 10% out, you've still got 27mpg or so. Even 5% error is fairly large for these devices so its possible.

Whats the gearing like on the car, I assume its quite tall despite being an AMG and say the engine is turning over @ 1800rpm @ 70mph its not really struggling.

 

[peterg1965]

Say its 10% out, you've still got 27mpg or so. Even 5% error is fairly large for these devices so its possible.

Whats the gearing like on the car, I assume its quite tall despite being an AMG and say the engine is turning over @ 1800rpm @ 70mph its not really struggling.

Gearing means that 70 mph equates to about 2000rpm so it is just a bit more than idling!

It is a lovely car to drive and not a milli second worth of regret yet!

 

[Howard]

I get 30 on the motorway Peter.

I'd say it's working fine. Your gearing sounds the same as mine 70mph / 2000 rpm.

 

[Dryce]

I suspect the OBC is over reading isn't it?

I've always found the readings from on-board computers to be a bit optimistic.

My current car has been out by about 5% when I've bothered to cross check with filling the tank. My previous car (not MB) was often 10% optimistic.

And if you had a tail wind on a long journey then that would also give the number a boost.

 

[Ted]

70mph 2000rpm
fan-bloody-tastic!!!!

I love high geared cars!!

 

[kwakdonut]

I think I've probably posted this before but.....you drive a CLK 55 AMG and you worry about fuel economy????!!!!!!!!!!

 

[robert.saunders]

I don't think he is worried about the mpg, only that the OBC is potentially reading high, not low

 

[kwakdonut]

Ah ok, I understand. Just because someone drives a car with a big capacity engine, doesn't automatically mean that it will get poor economy! Why do yanks drive cars with such big engines? Because they cover long distances at constant speeds. 3, 4, 5+ litre engines getiing 30-35 mpg is not uncommon really.

 

[Tan]

I wish I was getting that kind of MPG, the best that I have had so far is 24.9MPG on a run from Oxford to London.

On normal unleaded I was getting about 14mpg and now on Shell V power or what ever its called it is reading 19.8 on my regular drive from home to the City.

 

[Chattonmill]

When I used to travel down France regularly I was surprised that my Peugeot 306 1.9 Turbo diesel was less economic that the 2.6 V6 Audi Coupe, then I realised that at 110 mph the 306 was straining and the Audi wasn't even trying.

 

[peterg1965]

I think I've probably posted this before but.....you drive a CLK 55 AMG and you worry about fuel economy????!!!!!!!!!!

Who said I was worried about fuel economy? I was just making the point that it was delivering much more than I ever expected!

I drove home yesterday from London, and was a little more 'spirited' in my driving........ regretably the OBC fuel to just 30.3 mpg on that 245 mile sprint! I have done the brim to brim calculations and reckon that the computer is overreading by about 1 - 1.5 mpg. I remain extremely impressed that I can get nigh on 30mpg out of a 350bhp V8!


Note to self ........ must try harder (they all probably think I drive like a granny!)