Biodiesel has between 5-8% less BTUs. So for the sake of your statement and my math skills ,lets say it has 10% less power. Lets also assume they did sneak 5% into the mix. 10% of 5% is .5%. So half of 1% less power is causing a noticeable loss of mpg? I think you might be looking in the wrong place. If they did add even 3% biodiesel, it would more than make up for the lubricity loss in the ULSD.

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1987 300TD 309, xxx 2.8.2014 10,000 mile OCI


Be careful of the toes you step on today, as they may be connected to the ass you have to kiss tomorrow. anonymous

“Be who you are and say what you feel, because those who mind don’t matter, and those who matter won’t mind.” Dr. Seuss

I"ve come to a loose conclusion that the fuel is being mixed with something that affects newer Benz diesels. As i stated earier in this post, my wife's 97E300D has a very noticable drop in mpg s and my 85 300SD shows no change, I think this is a regional thing where certain regions do something to their fuel. Others on this site are getting good mpg s on their 96 or 97 E300D's . How many different refineries are there in this country? Are they dilluting it with something after it leaves the refineries ? Just shooting from the hip here, but what is going on? Jim

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1997 E300D Wife's daily driver
1985 300SD my daily driver
1999 Expedition family road trip and material hauler

Since the introduction of ULSD, I have noticed a 2 MPG drop with my MBZ's. My truck, 7.3 F250, dropped 3 MPG's. Added a chip to the F250 and picked up anywhere from 1.8 to 3 MPG, depending on how I drive it.

Everybody I know that runs the 7.3's has had a 3MPG drop that coincided with the introduction of ULSD. I know a lot of long time truckers who have also lost MPG's.

Sulphur should have nothing to do with the loss. It must have been something else they changed in the fuel.

Cheers,

Bill

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Cheers,
Bill

When the ULSD first hit the market, my 82 300SD dropped 2 MPG immediately, my LN 8000 Ford with a 6-71 Detroit dropped from 8.2 to 6.7. Mixing used motor oil into the ULSD did bring most of the mileage back on the old Detroit, but I was hesitant to run it in the MB. I have found that I can increase the mileage in my 94 F250 7.3 IDI by 1 MPG by putting 8 oz. of outboard motor oil per tank (19 gallons). These are just my observations over a period of time, not meant to be scientific at all.
I am a truck and heavy equipment mechanic and have noticed more customers with older, non-computerized engines complaining about the loss of fuel economy, but I don't have any figures to back this.
Jeff

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1971 R600 Mack toterhome (SuperDawg)
99 NU-WA Snowbird 34+2 SE 102 5er
If it's not diesel, it's not in my stable!
53 F100 617.951/auto
95 Dodge 3500 Cummins/5 speed service truck

Are you sure your 97 hasn't developed a fuel leak? If the mileage drop is due to the fuel you should have noticed it in both cars.

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2004 VW Jetta TDI (manual)

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

Yea... I was just throwing that out there. Got no idea really but figured it was worth mentioning as a small part of the whole. I'm not looking in any particular one place. I was suggesting we look in several places. Some of which are unknown or unmentioned. I think we can attribute some of it to USDL for certain. But again, our math doesn't work out to attribute all of it to just that. And even if we add some Bio Diesel BTU loss to it, we still got a ways to go. I can't see either ULSD and even some Bio accounting for all of it. But a portion of it... where's the rest? I got no idea...

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1983 300D-Turbo - Deep Blue w Palomino MB Tex (total loss in fire 1/5/09 RIP)
1995 E320 W124 Polar White/Grey Mushroom MB Tex
2005 F150 Supercrew - Arizona Beige - Lear topper
1985 Piaggio Vespa T5 - Black and Chrome

www.cphilip.com

Diesel Addict, fuel leak was my first thought and i went over thoroughly. Its dryer than a baptist picnic at the i/p and any other suspect areas. It is parked inside almost each night and there is no smell of diesel in the closed garage in the morning.
I dont know if we are still getting winter blend here. Mpg's may improve when summer fuel arrives. We will find out. Jim

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1997 E300D Wife's daily driver
1985 300SD my daily driver
1999 Expedition family road trip and material hauler

What about the injectors? There could be an external leak (under the black plastic cover) or one or more injectors could be spraying poorly which would definitely drop your mileage. Doing a Diesel Purge probably wouldn't hurt.

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2004 VW Jetta TDI (manual)

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

I got 33 MPG in the 300SDL going from FL to PA on Diesel fuel I bought on the road. I don't know if it was ULSD or not. That's the best I ever got, usually averages ~ 30MPG.

BTW, I use used engine oil as a fuel addititive.

I'm curious, what ratio are you running? I about to start back running used motor oil in my service trucks, but was hesitant to run it in my MB powered F100.

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1971 R600 Mack toterhome (SuperDawg)
99 NU-WA Snowbird 34+2 SE 102 5er
If it's not diesel, it's not in my stable!
53 F100 617.951/auto
95 Dodge 3500 Cummins/5 speed service truck

Used engine oil is a very bad thing to use as an additive. The sub-10 micron metal particles (which are small enough to pass through the fuel filter) will damage the pump.

If you want to burn engine oil, use new oil.

Cue "I've been burning liquified dog doodoo for 20 years without any problems!"

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1985 CA 300D Turbo , 213K mi

thanks for the lol moment

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'83 SD, 2x '85 SD
You are entitled to your own opinions, you are not entitled to your own facts.

Agreed. Don't burn used engine oil in any engine you care about. It's fine for a "junker" motor in your $500 beater, though. Even ATF isn't a good idea... ash deposits, etc... stick to normal additives if you need them (Red Line, Stanadyne, Power Service, etc).

Yeah, if you insist on burning oil, get some new, ashless 2-cycle motor oil. Regular oil, especially used oil, has things in it that are not meant to be burned.

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2004 VW Jetta TDI (manual)

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