W124 280TE Fuel Consumption

[alan280]

Can anybody shed some light on my situation regarding fuel consumption, most of my driving is on country roads (40-50 mph), shortish journeys 10-15 miles and I get 18-20 mpg. Ok thats seems fine for the conditions but when I go for a long run 150 miles non stop, motorway driving at steady 70-75 mpg I get the same fuel consumption 0f 18-20 mpg. Its a bit annoying because when I do get the chance, theoretically, to up the mpg, my car doesn't do it. I have had the car checked out by a good dealer, who checked the complete fuel system and then all the individual components but they found nothing wrong. They did say that I should be looking at getting somewhere around the 27 mpg mark but were at a loss to why I wasn't getting that.
Has anybody had a similar situation or can somebody suggest anything.

Thanks

Alan

 

[Alex M Grieve]

I had a similar car with 108,000 miles on it which we ran for 2 years and 14,000 miles around Warwickshire - mainly 15-20 mile journeys and virtually no longer trips.
Over that time it averaged 26.8 mpg, just a shade better than my wife's earlier 190 carburated! So the theoretical consumption is achievable. I am at a loss to know why you should be faring that much worse. It would take more than tyre pressures to explain the difference!

 

[alan280]

Thanks for reply.
Always forget data that may help, thus:-
125,000 miles, 1993, exhaust ok, tyre pressures checked regularly and a well looked car.

 

[petronious]

Would it make a difference dropping down to between 65 & 70 mph???

 

[Myros]

Our 300TE was theoretically thirstier

and we got 18-22 around town on shopping and school run, and on a 600 mile round trip to Devon and back, with the traffic pegging speed to 50-70 nearly all the way, just under 27 mpg ( well-loaded up) . Watching the economy gauge and easing back on the gas helps a bit.

 

[lakeside]

I get 28 mpg at 70-75 mph on motorway runs out of my E280, either fully loaded or empty. Is yours 4-speed or 5-speed?

 

[alan280]

I've got a 4 speed box. I drive this car grandad style, steady acceleration, cruising steadily with a lot of forward thinking. If I drove it with a heavy right foot then I'd be entering realms that my wallot would be cowering at!