I thought I taught you how to drive that thing. I can get 30 mpg IF I keep it down to 65 mph from here to Newington, CT and back. Getting it on a 617 is a whole different ballgame. I could do it, but, I'd have to keep the speed down to 55 mph. The shi*boxes would blow my doors off.

p.s.: Bet I get 50K out of my pads

Hatterasguy,

Yes a true 30 MPG It was right on 600 miles and 20 gallons filled it both times. I was surprised because I usually get 28 MPG. I have never done anything to the engine except valve adjustments and replacement of the water pump, V belts and front oil seal. You know me, "if it ain't broke, don't fix it".

I got 31 MPG once time but was at 50 to 55 MPH for about 450 miles with no stops.

You will cry when I tell how many miles are on my front pads. They were on the car when I bought it 138,000 miles ago. Odd though, I just had to replace the rear pads this week. But they were pads with rivets holding the friction material in place and they don't last as long. You can't use the friction material above and below the head of the rivet.

25 MPG sounds low for a 603. Maybe you need a tune up. LOL What kind of driving do you do? Pedal to the metal operation doesn't yield good fuel mileage nor does a lot of stop and go.

I Read Consumer Reports and there are very few cars that get an actual 30 MPG overall in their tests. And the ones that do are some little piss ant cars I wouldn't want.

P E H

I do take off slower from stop light's and time my moves better, but I always seem to need to use the brakes. For example I'm going 40-45 down the Bulivard getting passed as usual, and the light in front of me goes from green, yellow, red. For some reason the yellow seem's to be extremly short. So now I need to stop. I also do a lot of around town driving and again always seem to give the brakes a good work out. My front wheels will turn black in 300-400 miles.

As far as the highway, it is a Merc, the W126 comes together on the highway. With that turbine smooth 603 pulling and pulling, 100 comes up kind of fast. But mostly I cruise around 70 or slower, because of traffic, lots of traffic to fight. I only get to run her up once in awhile.

__________________
1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

P.E.Haiges if I drove 55mph on long trips I bet I would get 30+ to.

__________________
1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

I bought a container of "Power Service" conditioner at a truck stop in Ohio when I was out there. 12 oz. in 20 gallons will raise the cetane level by 6 points. I'm going to run six tanks of it and see how it does. The first tank yielded no benefit, but, I was stuck in stop and go traffic for at least 90 minutes. The second tank, presently, will also yield no benefit because I ran around Manhattan for two hours today in stop and go traffic. But, I am hoping for a return to 30+ even when running at 70 mph from here to Newington, CT and back. That would be quite something if it can do it.

I have been running Power Service since I bought my car, I just stopped this tank full and tried some ATF. The power service seems to make it respond better, I feel like I am pulling an anchor without it. But the ATF does make the engine run smother. Maybe I should try an ATF/Power Service cocktail this tankfull? Then I will throw in a 1/4oz of Biobar for good measure.

__________________
1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

So, Hattie, how much Power Service did you put in for every tank?

Have any back to back comparisons on fuel economy?

I don't remember! I figured it out once and found a container that holds the right amount, I just fill it and dump it in the tank. I'll have to check.

__________________
1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Hatterasguy,

Doesn't power service have a biocide in it? Adding Biobor won't make any mileage difference but it will keep you running because it will keep the fungus from pluging up your filters.

Do you put the ATF in the fuel tank? I've been adding used engine oil to my tank. Only about 2% but I can't tell any difference.

I had a fungus problem in my 300SD so I put in Biobor and so far no more plugged filters. That was the only time I had a fungus problem in 35 years of driving Diesels. Some place I got contaminated fuel and the fungus kept growing. Should all be dead by now, I hope.

P E H

Ive been using PowerService Cetane booster (6 number increase) and their Bio Kleen biocide for years. They are two seperate additives. I bought a 16 oz bottle of biocide about 3 years ago for $12 and finally used the last of it about two weeks ago.

Here is a link to PowerService with a listing of all thier products.

__________________
'10 Chrysler T&C Stow-N-Go White. Grandpa's ride.

'13 Chrysler 200 Touring Candy Red. Grandma's ride.

Age and cunning will always over come youth and vigor.

With six points on Cetane, I would think you could document some fuel economy gains. Have any back to back data for the 240?

I'm going to try and make a case for using it with the SDL, however, my data on the first two tanks is compromised.

Last time I was on a trip in the Ozark Hills (elev 400ft to 1200 ft) and these are sharp angle up hill roads and I was foot to the floor about half the time keeping it at 65 to 70 mph and I averaged 31 mpg for the trip. I am averaging 27 mpg around town and I drive foot to the floor till I get to the speed I want to go. Also the fuel I use is B2 & 49 cetane with 10 micron final filters on the pumps. I also have access to 50+ cetane fuel if I wanted to drive 50 miles one way to get the stuff, I do drive 25 miles one way for the B2 49 cetane fuel.

__________________
'10 Chrysler T&C Stow-N-Go White. Grandpa's ride.

'13 Chrysler 200 Touring Candy Red. Grandma's ride.

Age and cunning will always over come youth and vigor.

Are you starting with 49 Cetane fuel and adding the Power Service for another 6 points on top of that?

I am adding 8 oz's Brian with every fill up.


P.E.Haiges I got the Biobor cheap and have been adding a little less than a 1/4oz every fill up. Just in case. The reason I tried a quart of ATF last fill up was because some of the 603 experts were saying it would clean things out real well; and since I am always fighting a skipping problem I figured I might as well give it a shot. It did seem to make the engine run a little better. However it didn't give it the little extra punch that the power service does. I swear my engine spools up faster with that stuff.

__________________
1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Yes, and I'm adding enough for the 6 points so as to get as far past 50 Cetane on the fuel I can. When these engines were designed the average cetane value of the fuel in the US was mid to upper 50's in cetane value. Now the average cetane rating is 42 in the US. Currently in western Europe the cetane rating is running mid 50's and is much cleaner then our fuel.

Higher cetane = higher BTU= more HP= better MPG= less smoke= longer lasting engine

__________________
'10 Chrysler T&C Stow-N-Go White. Grandpa's ride.

'13 Chrysler 200 Touring Candy Red. Grandma's ride.

Age and cunning will always over come youth and vigor.