I took a little road trip this weekend...

On Sunday I came back to Waterloo from Oklahoma City, fully expecting SWMBO and Molly the dog to fly home Wednesday or Thursday.

I had been home for about an hour Sunday evening when SWMBO called at 7:30, saying that the airline wanted all kinds of BS paperwork before they'd haul a 50lb dog and that now she didn't need to stay up there after all. The long and short of it: she needed me back in OKC to get her and the dog. After a short nap, I was on the road at 2:00 am Monday, and back in OKC by 8:30 am. We left OKC at 12:30 and pulled into the driveway at 8:15 pm last night.

Aside from this being something of a forced march, it was a great opportunity to get some hard stats on Marlene's highway economy.

Trip stats:
873 miles in 13.25 hrs of drive time. Average speed: 65.8 mph.
34.5 gallons of fuel used. Overall average economy: 25.3 mpg (with a/c on the trip back)

Questions:
Is this routine economy for a 300TD that's clocking +225k miles? I'm impresed but, should I try for more? If so, what should I expect and what do I need to do to achieve that economy?


Regards to all,
Randy n' Marlene
Marlene = '83 300TD maroon/palomino, 223524 miles young.

R Leo,

What do you want , egg in your beer? That's not bad mileage and you would probably spend a lot more trying to improve it than what you would save.

If you you want a big improvement, you will have to get a CDI.

P E H

That's about what I would expect. There are MANY variables that factor into fuel mileage.

I drove my wifes '83 turbo station wagon from Texas to Wisconsin with full family aboard in the early nineties. I got 27MPG on the trip with a full load of everything that the family was unwilling to leave at home.

I drove almost all Interstate with cruise control set at 70MPH or so, it was before the 55MPH speed limit was revoked.

Have a great day,

PEH,
I knew you'd pipe up, you 'ol curmudgeon!

Larry,
It sounds like I'm pretty much 'on the marks' per your TD experience.



I asked because I didn't truly know what to expect. You see, haven't had this car all that long and had read the anecodal tales of 30 mpg MBZ diesels. I thought that if I should be getting 30 and was only getting 25 I better do something about it.

In actuality, I'm in total awe of a vehicle that can do 70-80 all day and still get 25 mpg all in style and with panache...well, um, as much panache as you could expect with a 20 year-old station wagon.

Thanks all,
R

I think you're doing OK MPG wise. We've all heard tales of better, but I think many of them originate from the Northeast, where 55MPH represents 'highway speed.' I never got much better than 24MPG out of my old 123 turbo, but then I never drove very near the speed limit either.

I had the misfortune of driving from Dallas down to Houston and back in my 1998 turbodiesel this past weekend. We stuck to the speed limit pretty much the whole way, so 70MPH most of the time. Did 575 miles on 17.5 gallons, so just shy of 33MPG - and that number includes a couple of days worth of suburban commuting.

BTW, diesel prices are incredibly low along I-45. I saw $1.47 quite commonly, and we filled up at a Mobil truckstop just North of Ennis for $1.43. All the stations are still above $1.60 here in Dallas.

- JimY

JimY,
The thing I find enigmatic is that it seems like it doesn't matter how I drive Marlene, her mileage stays practically the same.

This trip was unique in that the weather (wind speed, direction and temp) was almost identical on both days and since I was running the same stretch of road, it made a great opportunity for some comparisons.

For example, when I came back from OKC by myself on Sunday, we were most definitely "walking the dog." Several uninhabited stretches of Hwy 81 and 281 felt her passage at 90+. And, despite the speed, the trip segment from Duncan, OK to Hico, TX saw an acceptable 25.7 mpg

On the way back on over the same road Monday, I kept her reigned in to 75 so that SWMBO wouldn't rip out the right side armrest and bludgeon me with it's sharp stub. The same trip segment (running the A/C continuously this time) produced an astounding 26.5 mpg.

Musings on Diesel Prices:
The thing that amazes me is the variance in fuel pricing. In OKC I saw prices as high as 1.799/gal and all the way down to 1.309/gal. You didn't have to search far to find a deal in the 1.44 to 1.55 range.

Austin prices range from 1.799/gal at Shell (for something called "Premium Diesel"-whatever that is???) down to 1.609/gal out at the truck stop.

...hmmm, will my TD run better on "Premium Diesel?"

Later,
R

Better stay out of the Northwest. Lowest price I have seen around here for diesel was $1.85, most stations running it for $2.09.
Sounds better East of here.

SWMBO???
RT

__________________
When all else fails, vote from the rooftops!
84' Mercedes Benz 300D Anthracite/black, 171K
03' Volkswagen Jetta TDI blue/black, 93K
93' Chevrolet C2500HD ExCab 6.5TD, Two-tone blue, 252K

My 82 300TD gets about that milage.

The 99 E300 gives us 38 MPG going and coming to Oklhoma State to see the son.

It is for sale!!!!!!!!!!


Dave

__________________
1970 220D, owned 1980-1990
1980 240D, owned 1990-1992
1982 300TD, owned 1992-1993
1986 300SDL, owned 1993-2004
1999 E300, owned 1999-2003
1982 300TD, 213,880mi, owned since Nov 18, 1991- Aug 4, 2010 SOLD
1988 560SL, 100,000mi, owned since 1995
1965 Mustang Fastback Mileage Unknown(My sons)
1983 240D, 176,000mi (My daughers) owned since 2004
2007 Honda Accord EX-L I4 auto, the new daily driver
1985 300D 264,000mi Son's new daily driver.(sold)
2008 Hyundai Tiberon. Daughters new car

She
Who
Must
Be
Obeyed

Randy,

There have been a few threads on this forum discussing this topic in detail. The short answer is that no, your MPG is not great, but you could spend an awful lot of time and money trying to improve it with zero results. If it makes you feel any better I have chased this problem on my '84 for over a year and it still never gets above 24mpg. I wouldn't lose sleep over it, but if you must tinker with it, here's some things to check (in no particular order):

Clean air & fuel filters
Brake pads - make sure they're not dragging
Tire pressure (32psi+)
Valve adjustments (required every 15kmi)
Timing chain stretch (want 4 degrees or less)
Try Diesel Purge treatment (2 cans)
Make sure engine temp is above 80C
Make sure odometer is not intermittently stopping (!!)
Check injection pump timing
Have injectors pop tested


Good luck,

__________________
Dave
Boise, ID
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