Newbie s212 e250 CDI estate 2011 MPG

[Gazwould]

Isn't the strain on them at start up , so nothing to do with BHP & torque ?

 

[Suhail Khan]

No idea pal.i know noise it made on start up if chains are faulty

Just want to know if remaps are not recommended for these engines altogether

 

[Suhail Khan]

So i changed my whel size from 18" merc rims to 16" - did a manifold clean, time ng chain tensioner and tyre size went down from 245/40/18 to 205/55/16

After these jobs i went on my first long drive,i could believe my eyes. 61.4mpg on my first 230 mile trip to scotland and then 62.8mpg on my return today. Its goven me 630miles and my fuel light hasnt come on yet. This was steady 70mph with slow acceleration, using momentum of the car to hold the speed. On the same trip previously ive been about 10 times, i couldn't get over 50mpg on screen no matter how hard i tried.

I am over the moon but very surprised as to why its suddenly gone up.
Is it the reduction in tyre and wheel size thats improved the mpg!?

Its given me 630miles from 50litres which is a real 57mpg!!!! I tried this from rim to rim so i know it's accurate .

 

[A.J.]

So i changed my whel size from 18" merc rims to 16" - did a manifold clean, time ng chain tensioner and tyre size went down from 245/40/18 to 205/55/16

After these jobs i went on my first long drive,i could believe my eyes. 61.4mpg on my first 230 mile trip to scotland and then 62.8mpg on my return today. Its goven me 630miles and my fuel light hasnt come on yet. This was steady 70mph with slow acceleration, using momentum of the car to hold the speed. On the same trip previously ive been about 10 times, i couldn't get over 50mpg on screen no matter how hard i tried.

I am over the moon but very surprised as to why its suddenly gone up.
Is it the reduction in tyre and wheel size thats improved the mpg!?

Its given me 630miles from 50litres which is a real 57mpg!!!! I tried this from rim to rim so i know it's accurate .

I would have thought it would have gone the other way, the smaller wheel would have to spin faster, albeit the tyre walls are taller. Maybe one cancelled out the other.

 

[Srdl]

I ran two BMW 3 series back to back, with 16in and then 18in, back in the day and didn’t get any change in mpg. The 16in tyres lasted twice as long as the 18in ones though.

 

[mioba]

cant see at all how changing tyres have any effect on fuel economy to the extent you mention, The engine pulling the same lump.

Possibly more related to manifold clean that you mentioned

 

[Blobcat]

Wider tyres equals more rolling resistance and lower fuel economy.

Have a look at any manufactures data sheets and you’ll see higher emissions figures for the same car with bigger wheels and wider tyres. It’s why so many come with narrow tyres now to reduce the emissions figures.

 

[malcolm E53 AMG]

Wider tyres equals more rolling resistance and lower fuel economy.

Have a look at any manufactures data sheets and you’ll see higher emissions figures for the same car with bigger wheels and wider tyres. It’s why so many come with narrow tyres now to reduce the emissions figures.

The very reason I can’t get anywhere near the mpg figures of the S210 E320cdi (50mpg on a good run) which was on 215mm wide tyres all round compared to the S212 E350cdi (best I’ve seen is 42mpg) on 245mm front and 265mm rear tyres - retrograde progress on emissions unfortunately but the tyre manufacturers must love the profit from the lower section tyres

 

[Ridleyrumpus]

Haven't you gone from a wheel/tyre combo with a diameter of 19.3" to one of just about 18"?

This would mean that fir each revolution of the wheel you would have travelled further with the original tyre/wheels than you have on now.

Unless the cars computers know this won't you both be showing a higher speed than you actually are going AND a greater distance travelled for the same number of revs of the wheels?

If I am right then comparing the distance travelled speed on the cluster with that on a sat nav would show a discrepancy.

So i changed my whel size from 18" merc rims to 16" - did a manifold clean, time ng chain tensioner and tyre size went down from 245/40/18 to 205/55/16

After these jobs i went on my first long drive,i could believe my eyes. 61.4mpg on my first 230 mile trip to scotland and then 62.8mpg on my return today. Its goven me 630miles and my fuel light hasnt come on yet. This was steady 70mph with slow acceleration, using momentum of the car to hold the speed. On the same trip previously ive been about 10 times, i couldn't get over 50mpg on screen no matter how hard i tried.

I am over the moon but very surprised as to why its suddenly gone up.
Is it the reduction in tyre and wheel size thats improved the mpg!?

Its given me 630miles from 50litres which is a real 57mpg!!!! I tried this from rim to rim so i know it's accurate .

 

[Ridleyrumpus]

Made a slight mistake,
old diameter 21.2" circ 66.6
New 20" circ 62.8

So about 6% difference.