Real World Fuel Economy?

[Peter De La Mare]

I had a single tank last 510 miles during my ownership of a 2001 E320 Est petrol, 35.5mpg overall from it's 65 litre tank. It was very low on fuel when I refilled it, as I needed 65.01 L to fill it !

If I hadn't had to suffer 2 hours driving through the middle of London between M4 and Canary Wharf during the trip then I reckon it would have been over 36mpg.

This trip was from Canary Wharf to a shooting ground deep in the countryside in Reading (5 miles of country lanes) then to Tiverton in Devon and then back to Canary Wharf. Both the London parts took an hour at an average speed of 15mph.

 

[47p2]

I've been to Fort William and back today. The journey north wasn't too bad considering I left Glasgow at 2.30pm and with the sun shining was expecting a lot of traffic at Loch Lomond. From Dumbarton to Balloch was a bit busier than usual but once I passed there it was not too bad.
When I arrived at my destination the MPG was showing 43.6 and a journey time of 2.5 hours. Coming back however was a total nightmare as the traffic from 2 miles north of Luss to Balloch was nose to tail, a distance of 12 miles and a time of 1 hour, so that killed any record breaking fuel consumption attempts I had.

13 miles out of Fort William I checked and this is what my fuel consumption was

15 miles into the journey was even more impressive

78 miles after leaving Fort William and I was still amazed

Sadly an hour and 12 miles of stop starting killed that and I hobbled home to this

All in all not too bad for an old diesel burner. My W140 would have consumed twice as much fuel on the same journey.

Here are a few pictures taken today

Ready to leave

Glen Coe

 

[jberks]

So Whitenemesis with his C270CDI is leading on the 60 ltr tank with 520 miles for 56 ltr and for the 80 ltr tank I have 708 miles for 79 ltr in my E320CDI. Any one else with higher figures? or even close ones for the petrol variants?

I was well on track with 680 on the trip and the computer reckoning I still had another 100 miles left in the tank, then the motorway ground to a halt and I had to spend an hour crawling through Manchester rather than cruising home at a steady 80 - so filled up with 77 litres at 718 miles = a bit over 42mpg. Very happy with that for a steady 80 up and down the pennines and I reckon without Thursday's debacle I may even have nudged 800 miles to a tank but as for the computer, it normally shows 45-46 mpg when I park up, so it's around 9% optomistic.
You can trick it by freewheeling. Cruising along it reads quite accuratley I suspect but drop the throttle and let it slow for a jam on it's own and the MPG reading starts clicking up quite quickly. I'm sure it does help with mpg but 1/2 a mile of freewheeling can often improve the reading by 2-4mpg which is clearly not realistic.

 

[Alex M Grieve]

I've been to Fort William and back today. The journey north wasn't too bad considering I left Glasgow at 2.30pm and with the sun shining was expecting a lot of traffic at Loch Lomond. From Dumbarton to Balloch was a bit busier than usual but once I passed there it was not too bad.
When I arrived at my destination the MPG was showing 43.6 and a journey time of 2.5 hours. Coming back however was a total nightmare as the traffic from 2 miles north of Luss to Balloch was nose to tail, a distance of 12 miles and a time of 1 hour, so that killed any record breaking fuel consumption attempts I had.

13 miles out of Fort William I checked and this is what my fuel consumption was


15 miles into the journey was even more impressive


78 miles after leaving Fort William and I was still amazed


Sadly an hour and 12 miles of stop starting killed that and I hobbled home to this

All in all not too bad for an old diesel burner. My W140 would have consumed twice as much fuel on the same journey.

Well done sir. I agree that the W 220 with the IL6 diesel takes a bit of beating on fuel economy. I never managed to see more than 50 mpg on instantaneous read out of mine, but I rarely saw less than 70 mph on the speedometer either!

Part of the secret is the CD (coefficient of drag) which at 0.27 is less than the much vaunted Jaguar XF (0.28).

My S Class averaged 39.9 overall in the 3.6 years I had it, which I though t was good and was reflected in negligible wear on tyres and brakes.

I wonder how the W 221 compares on these parameters? The V6 is certainly a very smooth engine and the 7 speed box is seamless in operation, but is it more fuel efficient?

 

[47p2]

The road down from Fort William on a sunny Sunday evening is terrible. There is no way the journey could be done in 2 hours or less so it's a case of just slot into the line and follow the leader. Travelling like this I tend to sit far enough behind the car in front so that I don't need to brake every time he brakes therefore saving fuel.

Alex, having a look at my OBC my overall average mpg for the last 3982 miles has been 41.3mpg. An unbelievable consumption when you look back a few years to when 2 litre petrol engines were achieving a miserable 25mpg. My W140 320 petrol would average around 22mpg and I thought that was good, the best I saw from that was 32 and the worst was 16

 

[Alex M Grieve]

Over the sea to Skye

Skye trip average mph49trip av mpg42.2hours26gallons29.1miles1282mpg44.1

Data from our holiday to Skye from Warwickshire in the W 200 in 2008. The OBC said 42.2, but "brim to brim" was 44.1 mpg.

The trip on that car was always a bit conservative.

 

[aquiss]

I've have never reset my W204 C-Class since I took delivery of it, so I think i prob have one of the best examples of the fuel economy.

As you can see, the figures quoted by Merc and those happening in the real world are something different

 

[Naraic]

I've been to Fort William and back today. The journey north wasn't too bad considering I left Glasgow at 2.30pm and with the sun shining was expecting a lot of traffic at Loch Lomond. From Dumbarton to Balloch was a bit busier than usual but once I passed there it was not too bad.
When I arrived at my destination the MPG was showing 43.6 and a journey time of 2.5 hours. Coming back however was a total nightmare as the traffic from 2 miles north of Luss to Balloch was nose to tail, a distance of 12 miles and a time of 1 hour, so that killed any record breaking fuel consumption attempts I had.

13 miles out of Fort William I checked and this is what my fuel consumption was

15 miles into the journey was even more impressive

78 miles after leaving Fort William and I was still amazed

Sadly an hour and 12 miles of stop starting killed that and I hobbled home to this

All in all not too bad for an old diesel burner. My W140 would have consumed twice as much fuel on the same journey.

Here are a few pictures taken today

Ready to leave

Glen Coe

New bridge in the back ground. I was there in 2008, the bridge was still being built.

 

[dieselman]

Well done sir. I agree that the W 220 with the IL6 diesel takes a bit of beating on fuel economy. I never managed to see more than 50 mpg on instantaneous read out of mine, but I rarely saw less than 70 mph on the speedometer either!

Part of the secret is the CD (coefficient of drag) which at 0.27 is less than the much vaunted Jaguar XF (0.28).

My S Class averaged 39.9 overall in the 3.6 years I had it, which I though t was good and was reflected in negligible wear on tyres and brakes.

Try blanking the radiator grille and lowering the car 25mm. You should see a theoretical reduction of drag down to a CD of 0.25 or 0.24.

If you achieve consistent figures you might be able to monitor a change, hopefully for the better.

 

[Clarence]

If it is of interest, took my 2006 E280 CDI to France a couple of months ago. Drove from Dreux to Aigues Mortes on the south coast over day and a half (no time pressure) brim to brim used 51 ltrs to cover 495 miles ie 43.6 mpg.

That was about 115 miles on ordinary roads average 44 mph incl slow going around Montpellier, the rest on motorways avg just under 70 mph. Motorway climbed from sea level to abt 3,500 ft, over the Millau bridge then back to sea level.

Not claiming any record but quite impressed with that figure for a fairly large well laden 6 cyl auto.

 

[47p2]

New bridge in the back ground. I was there in 2008, the bridge was still being built.

Different bridge 12ts, I was parked up on a side road when I took the picture, the bridge you are showing is now finished after about 2 years of construction work and it is further south from where I was parked. I would suspect the road I was on would be the 'old' original road through the glen

 

[Ben Longden]

You asked for real world economy.

This shot was taken on flat ground (its pancake flat for 200km in any direction, here) at 100Kmh on cruise control on the open road.

I reckon its indicating 8.5L/100Km

I filled up before the trip to my foster sisters place, 130Km away and then filled up on arrival.

En route there are several large towns with traffic lights, and so there is a bit of city cycle in there as well.

The end result for a city/highway cycle?
10L/100Km.

Thats from a two tonne W140 fitted with the 4.2 litre V8

The locally made family sedans from Ford and GMH regularly spruik 11L/100Km on the open road.

Pretty darn good, I think.

 

[television]

You asked for real world economy.

This shot was taken on flat ground (its pancake flat for 200km in any direction, here) at 100Kmh on cruise control on the open road.

I reckon its indicating 8.5L/100Km

I filled up before the trip to my foster sisters place, 130Km away and then filled up on arrival.

En route there are several large towns with traffic lights, and so there is a bit of city cycle in there as well.

The end result for a city/highway cycle?
10L/100Km.

Thats from a two tonne W140 fitted with the 4.2 litre V8

The locally made family sedans from Ford and GMH regularly spruik 11L/100Km on the open road.

Pretty darn good, I think.

That is very good for that car, even a Ford Fiesta 1.4 used 7.2 when your car was made

 

[HERBIEMERCMAN]

i am an MPG freak all be it i know it should only be an issue for certain motorists and not an issue for : company car owners, business owners, and politicians bankers and high earners and finally like me the owners who only cover a few miles per yr. if you ask any of them what their MPG is they will either be insulted or just say they have no idea. many of this group of people with the exception of the low mileage people don't even fill their tanks, others do it for them. business owners stick the cost on their prices, same as the bus/train and taxi companies do.
SO the motorists who will know their MPG are the less well off average worker who have to travel to work by car,or public transport, they are really feeling the squeeze, they also probably own the older big cars which mop up the fuel.
my car is a 1997 e-300. eleg. 7 seat est. which i have owned from new and now has 202,000 miles on the clock, i just watch my MPG as i like to think the machine is working at it's optimum performance. i average 26 urban to 34 MPG longer journeys and i have the EGR mod from dieselman's posting and add 200cc's of basic 2t oil to every tank of fuel. i am happy with this for such a smooth comfortable 14 yr old car which will carry 7 people. herbiemercman.

 

[GregW]

My 220CDi C class - trip computer always optimistic.

why is this...

 

[st4]

Averaging 37mpg in mine, which is quoted average for it. Its very good for what it can do