240D Milage - PeachParts Mercedes-Benz Forum

Guest987 · #1 07-11-2019, 12:34 PM

I stopped to fill the MB on Monday. I always check the mpg at each fill up. I noted it was 400 miles, since the last fill up. The last fill up was 398 miles. I was just amazed that the distance on both fill ups were so close(just 2 miles apart). I noted the mpg was 32.780. I always run in the 31 to 33 mpg consistently.

koooop · #2 07-11-2019, 01:28 PM

We've never even seen 30mpg with ours, usually 22ish city 27ish freeway.

t walgamuth · #3 07-11-2019, 01:44 PM

thirty is very good. Are you running smaller than stock tires? (in height).

martureo · #4 07-11-2019, 02:56 PM

I know its a bit different, but my 300D isn't far off from that.

You might be able to find a few more 240D's in the same range as you here.

Mercedes-Benz 240D MPG - Actual MPG from 58 Mercedes-Benz 240D owners

barry12345 · #5 07-11-2019, 03:14 PM

A little more than high average for a 240d. What form of driving do you do? Remember to really pin the milage down requires an average of many tank fulls if real accuracy is desired.

Human nature tends to be optimistic. Two forty Ds break into two specific groups I have noticed. Those that get about 25mpg and those that get about 30 on the highway..

Odometer error because of smaller tires was mentioned. Usually it takes a very long road trip to establish true highway millage. At least you seem to be in the group of 240d owners that get decent fuel millage.

Another effect on really hot days. My 1.6 jetta diesels got a signifigant millage improvement. This was quite noticeable as the increased distance between fill ups was substantial when hot out. Not that it was that great a thing as fuel was cheap back then. The 240s to the best of my knowledge do not have this trait or it is small. Many 1.6 owners mentioned it at the time as well.

barry12345 · #6 07-11-2019, 03:23 PM

Quote:

Originally Posted by martureo

I know its a bit different, but my 300D isn't far off from that.

You might be able to find a few more 240D's in the same range as you here.

Mercedes-Benz 240D MPG - Actual MPG from 58 Mercedes-Benz 240D owners

The turbo 5 cylinder engines are both more powerful. Plus usually give better fuel millage than the 5 cylinder naturally aspired cars. This may just be the higher rear end ratio on the natural aspired engines.
In fact the turboed engines in general compete well with most 240ds for fuel milage. That 26.7 you post is representative of mixed driving. On mixed driving usually more city or area milage is incorporated than highway. A 240d cannot achieve this much I believe in similar driving.

t walgamuth · #7 07-11-2019, 04:32 PM

The 300na engines are geared taller than the 240 but were only offered with automatics in the us. the turbo engines are geared taller. I think they all would deliver similar mileage if geared to take advantage of what tranny is in the car.

I had a us 240d car which I put in a euro 300 n, 307 rear end and five speed od stick. It would deliver 40 mpg with regularity highway if not driven too fast....say 65. That car would go 100 mph in fourth or fifth gear.

I also had a 300cd which I put a four speed stick in and I believe given the same gearing as the na it would do about the same economy with the turbo.

79-240d · #8 07-11-2019, 05:28 PM

My 240D averages 20.0 mpg on the dot (tracked over 4000+ miles) in mostly city driving. I'd love to see mid-20s regularly, let alone 30 mpg.

barry12345 · #9 07-11-2019, 08:50 PM

Quote:

Originally Posted by 79-240d

My 240D averages 20.0 mpg on the dot (tracked over 4000+ miles) in mostly city driving. I'd love to see mid-20s regularly, let alone 30 mpg.

I have to start out by mentioning. The 240ds will do on average worse if they have an automatic transmission. How much worse I do not know. It is reasonable to still see this five mile per gallon difference issue with them as well though.

Your car possibly falls into the maximum of 25 miles per highway gallon. I have never found a reason for the discrepancy between various 240ds.
One poster claimed he purchased his new and he never ever saw better than the 25 miles per gallon. On highway trips.

It may be driving style but I do not buy that. We all drive I suspect enough the same on highway trips we should not see a five miles per gallon difference. That said a good tune up may improve things somewhat.

It never hurts to check for dragging calipers. I noticed the other day that a rebuilt caliper I replaced a year and a half ago is dragging a little more than the others. I periodically wet my finger and check the wheel temperatures.

I coast to a stop and expect the wheels to be cold or all about the same temperature. For the test. A common problem when changing pads is to not clean under the old pad sliders and lubricate before installing the new sliders. The rust expands and should be filed ground or sandblasted off. Wire brushing just polishes it. I never bother to lubricate the end of the pads as the sliders are stainless steel. I guess you could use a trace. The high temperature caliper grease is expensive but a container lasts a very long time for a guy like me. Many if not most places do not do brakes really properly. At least in our rustbelt area. For the conditions they develop.

On a lot of short trips in a town or city. You might improve millage by using synthetic oil. From a cold start it takes some time to get that oil warmed up if it is conventional. The oil drag is really heavy on these engines when cold. Synthetic oil does not appear to have the heavy viscosity when cold.

t walgamuth · #10 07-11-2019, 09:32 PM

25 mpg sounds right for an automatic car.

Guest987 · #11 07-12-2019, 09:34 AM

I do have the correct tire size on the car. It is a 4 speed gear box. It does do what I said on the mpg. but I drive it like a stick transmission is supposed to be driven. I go to neutral coming up to a stop, and I leave it that way till the time to go. It will do that mileage with a combination of city and highway driving. It's a Mercedes what more can I say?

t walgamuth · #12 07-12-2019, 10:04 AM

Quote:

Originally Posted by Guest987

I do have the correct tire size on the car. It is a 4 speed gear box. It does do what I said on the mpg. but I drive it like a stick transmission is supposed to be driven. I go to neutral coming up to a stop, and I leave it that way till the time to go. It will do that mileage with a combination of city and highway driving. It's a Mercedes what more can I say?

I don't believe The size tire specified by mb is still available.

Once you describe it as combination driving it becomes an un-measureable entity.

We're not picking on you. Some of us have done a million miles driving similar cars. We are hopeless diesel nerds and cannot resist commenting on such a thread.

martureo · #13 07-12-2019, 11:03 AM

Quote:

Originally Posted by barry12345

The turbo 5 cylinder engines are both more powerful. Plus usually give better fuel millage than the 5 cylinder naturally aspired cars. This may just be the higher rear end ratio on the natural aspired engines.
In fact the turboed engines in general compete well with most 240ds for fuel milage. That 26.7 you post is representative of mixed driving. On mixed driving usually more city or area milage is incorporated than highway. A 240d cannot achieve this much I believe in similar driving.

My commute is largely country and highway. 35 mph roads and 70 mph highways. Very few lights or stop signs. Lots of rolling hills.

If I drive nothing but highways and longer trips I end up in the 29 -30 mpg range.

vwnate1 · #14 07-12-2019, 11:34 AM

I've owned a '82 240D for over twenty years, it used to get 26 + MPG all the time and on more than a few long Desert trips returned 32 ~ 34 MPG's with the car fully loaded and AC on max.

It's a slushbox, I try not to exceed 60 ~ 65 MPH when out on the open highway .

Last year I rebuilt the engine, broke it in carefully,rebuilt injectors and injection pump, no smoke and runs great but can't seem to get over 25 MPG anymore, once in a while I get 23/24 MPG's out of a tank .

Bummer this .

I still love the car though

.

t walgamuth · #15 07-12-2019, 11:39 AM

Possibly it is tough to match the precision work on the factory pump and injectors? Probably a small difference in set up in the pump might be the difference too.