I've managed to get 25 mpg on a couple of occasions. I'm curious about what kind of mpg other CA car owners get and if anyone knows about tricks (CA specific, there's lots of info. generally) to increase the mileage.

I think I read on here that the EPA estimate for these cars was 21 city, 22 highway. If so, I'm not doing too bad. Most of the time I seem to get at least 23.5.

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Ralph

1985 300D Turbo, CA model
248,650 miles and counting...

My '82 300D used to get me 24 mpg in a mix of city and highway driving. The CA version is known to get 1 or 2 mpg less because of the extra emission hardware. I would say you have nothing to worry about.

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2004 VW Jetta TDI (manual)

Past MB's: '96 E300D, '83 240D, '82 300D, '87 300D, '87 420SEL

In my 82 I get 26 city and 28 hwy. I got a big boost in mileage when I adjusted my pump timing. Use this method no special tools required.
http://diymbrepair.com/easley/iptiming.htm

I see you are as unfortunate as I was to buy an 85 Kalifornistani version.

First things first on fuel mileage. Check your tire pressure and make certain your suspension and alignment is good. Make sure you have a clean air filter. Adjust your valves. If these are not right your mileage is going to suck.

After that make sure you have had the trap oxidizer recall work done.(Unless of course your trap ox was stolen and someone put in federal emissions manifolds and turbo ) Before I had the trap ox recall work done I got 21 mpg in town and almost 23 mpg on the highway. After I had my recall work done I got 21 mpg in town and 25 mpg on the highway.

If you had the trap ox work done ever so often take your car up and down some steep hills in third for an hour. Floor it going up the hill to get the trap ox hot. On the way down the other side let the engine do the braking to force fresh air through the engine. When the fresh air hits the hot trap ox it burns out the crud that plugs the trap ox up.

If you don't know when the transmission filter was replaced last change it. If the transmission filter plugs on these cars the transmission tends to start slipping in 3rd and 4th. This is never good for mileage.

(warning! this is a controversial statement on this forum )
Check your boost level. If your boost level is low you will not extract as much power out of the same amount of fuel. The easy to understand concept is the more air that is packed into the cylinder the more energy it takes to raise the temperature of that air. If combustion chamber temperatures are reduced, less heat energy is robbed by the cooling system and more goes into powering piston. The much more difficult reason to grasp involves math and the specific heat ratio of air. I won't go into that here right now.

Your boost level should be 11 to 12 psi if its in spec. If you want more turn it up. Don't go past 14.5 psi because the stock turbo starts getting less efficient fairly quick.

Here is a tip that helps a little. Paint your exhaust manifold white with high temperture paint. This keeps it from radiating heat to your intake manifold. It also keeps the exhaust gasses hot which helps keep the trap ox clean. The hotter exhaust gasses also have more energy for the turbocharger's turbine wheel to extract. While your at it paint your turbocharger's turbine housing white(keep the center section and the compressor housing the same). If you have paint left get as much of the down pipe as you can. This will help keep heat out of the engine compartment. I intend to wrap my trap ox with insulating wrap later. I'm going to wrap the exhaust manifold If I can find another as a spare.

Your air recirculation valve is on your turbo's compressor housing to keep the trap ox from plugging up while driving at lower rpms. It opens and closes changing the EGR ratio. When it opens you get more EGR to cause a rich mixture causing unburned fuel to flow into the trap ox. When it closes the EGR gets reduced giving you a slight lean mixture causing some oxygen to flow into the trap ox. When the unburned fuel in the trap ox gets hit with the excess oxygen it burns causing heat which gets/keeps the trap ox up to operating temp. (Wouldn't you know it, some how the vacuum line going to the ARV got plugged up on my car. Darn! Now I have to drive my car hard from time to time )

The best highway mileage I have had was 31 on the trip home from the Portland / Washington GTG in Cougar, however I'm suspicious of that.
This last fill up however I got 24 mpg in town and 27mpg on the highway which is mostly due to the fact I'm running summer time diesel fuel now.

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green 85 300SD 200K miles "Das Schlepper Frog" With a OM603 TBO360 turbo ( To be intercooled someday )( Kalifornistani emissons )
white 79 300SD 200K'ish miles "Farfegnugen" (RIP - cracked crank)
desert storm primer 63 T-bird "The Undead" (long term hibernation)

http://ecomodder.com/forum/fe-graphs/sig692a.png

I get 28-29mpg at below 65-67 mph Freeway, City driving only about 23mpg almost at stop and go traffic I use 50% WVO and 50% dino fuel, it is a CA wagon (see bellow EPA estimates for a new car in 1985)

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2000 430 ML
2005 S500
87 300 D
61 300 restoring

Mine is a CA version, w/ trap recall completed, and I always get around 21 mpg in town and 23 on the highway. Got as high as 26 mpg once driving across west Texas (very flat) at ~65 miles per hour. Yesterday evening I drove the Volvo from San Antonio to Eagle Pass and back --314.8 miles round trip, filled up right away w/ 7.7 gal. of diesel, so approx. 40.8 mpg with the A/C OFF. The Volvo consistently gets 8-10 mpg better than the MB, even in town. But I didn't buy the MB for the mpg...just think they are well-designed, impressive automobiles, plus you can actually pass people, which you pretty much cannot do with the n/a Volvo engine.

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Christopher
'06 Mercedes E350 station wagon (silver/black)
'85 Mercedes 300D (black pearl/palomino)
'85 Mercedes 300SD (smoke silver/burgundy)
'79 Cadillac Sedan DeVille

'05 Toyota Camry (because always running is nice)

'85 Mercedes 300D sold back to orig. owner 8-1-06
'84 Volvo 264GL Diesel, owned 2000-2013

My 126 used to get 23 mpg night and day.

I have not driven my 210 long enough to comment.

SDL is a CA model. Gets 23.5 all day long. Although by the time the 603 rolled out the differences were pretty small.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Do you have a good pic of the air cleaner assy from that Kali Emission Kar?

An idea came to me about 5am yesterday.

EDIT - does the '85 Kali Emission Kar have that breather return line that usually runs from the air intake?

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I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

20 mpg, driving it hard on highway and city combined with AC always on and cold.

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'85 300D Turbo - CA Version

20-22 mpg on both cars (240d and 300sd)

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DCM

1977 240d
1980 300sd
1987 Chevrolet Suburban

I was consistently getting either 23.5 or 26 depending on the blend of suburban/highway use in my Cal 85 300D. It's had the trap oxidizer recall work. However, I just adjusted my turbo boost pressure and reseated my wastegate valve which was slightly leaking so I'm hoping to see see some improvement. All things considered, I'm pleased with the MPG given the size, weight, ride, safety etc.

Question: I also just pulled the vacuum line off my EGR valve and plugged it. Could this adversely affect my oxidizing catalyst? (replacement for trap oxidizer under the recall).

Gene

as i did some reading on this forum, it wouldn't hurt to disable the egr, in fact, its advantage is a cleaner intake manifold.

my question is how hard is it to perform what you did on your turbo boost pressure adjustment and wastegate reseating. can you post some procedures. thanks!

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'85 300D Turbo - CA Version

Pretty constant.
Michael

Wow, thanks for the info., guys. Conn, you must have spent quite a bit of time posting that! I think I might try the idea with the paint when I get a chance. I have had the trap ox recall work done.

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Ralph

1985 300D Turbo, CA model
248,650 miles and counting...