Quote: Originally Posted by greasybenz It seems as though the car gets better mileage with a synthetic. And this was the same with my diesel. Back when i had the 300SD i used delo 400 15w40, performance wise it was the same clackity ol diesel. But when i switched the the 5w40 synthetic my mpg's went up and the cold starts were better. The increase in mileage there was probably due to the change to the thinner viscosity of the 5w vs 15w! A thinner oil is easier to pump! The question is whether it is appropriate for your climate/weather before the next change. By spec, synthetics are supposed to be compatible with dino oils. That said, mixing to obtain a particular viscosity or just to save money is compromising the additive packages, and who knows what you'll get. Why not just use what is recommended by the manufacturer and change it at the recommended intervals. They have indeed done a lot of study on what oils to approve. Why try to second guess them? There are plenty on the list that do not cost an arm and a leg. Check out their listing at http://www.whnet.com/4x4/oil.html. Gerry Visel

Has anybody tried the Quaker State SUV Semi Syntetic 15W40 ? It says for SUV's on it, but i figure it should work fine on any dino taking mercedes. Has anyone out there tested it out yet?

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My Cars
Mercedes CLS
Mercedes C-Class W203 - All time favorite

R.I.P.
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Mercedes ML - Warrior
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CLEAR WINNER! Quaker State SUV Semi Syntetic 15W40

I have switched over to this oil, and oh boy what a difference it makes! My car hasn't ran this well and felt so powerful in a long time. It's great for Dino car's and gives the added Synthetic properties. I personally have had a great experiance using this oil in my C-Class and would recommend it to everyone. The only odd thing is the bottle saying its a blend for SUV's, but 15W40 is what I need.

I only know one place in canada where they sell it: LORDCO $4.59/litre

For the US, I don't know.

__________________
My Cars
Mercedes CLS
Mercedes C-Class W203 - All time favorite

R.I.P.
Mercedes C-Class - W202 Lemon
Mercedes ML - Warrior
VW Jetta – Worst Car I ever owned - Alot of problems

If you are so pleased with semi-syn, just think of the possibilities of using a full syn - better cold starting, longer drain intervals, far better wear characteristics, etc.

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George Stephenson
1991 350 SDL (200K and she ain't bent, yet)
former 2002 E320 4Matic Wagon - good car
former 1985 300 CD - great car
former 1981 300 TD - good car
former 1972 280 SEL - not so good car
a couple of those diesel Rabbits ...40-45 mpg

Problem is I can't find 15W40 in full synthetic....

__________________
My Cars
Mercedes CLS
Mercedes C-Class W203 - All time favorite

R.I.P.
Mercedes C-Class - W202 Lemon
Mercedes ML - Warrior
VW Jetta – Worst Car I ever owned - Alot of problems

I can only chuckle when I hear someone talk about how "well and powerful" their car runs just from switching oil type... a true definition of the word "placebo".

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95 E320 Cabriolet, 140K

i mix them sometimes.

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins& six speed; I have had about 35 benzes. I am finishing a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual....I also have a 427 Cobra replica with an aluminum chassis.

Or a real way to tell if someone knows something about the way their car runs or not. I know what every tick, knock squeak and squeal is in every one of my cars (except for a squeak in the tailgate of my Jeep I dont care about fixing at this time). And I can tell if they become quieter (or stop all together). I would only hope to god's sake other people can tell the same.

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Current:
1999 Chrysler 300M - 211,xxx
2014 Jeep Grand Cherokee Limited - 61,xxx

My Mercedes Benz 108 and 109 resource site

Previous:
1972 280SE 4.5 1992 Jeep Cherokee Laredo "Jeepy"
2006 Charger R/T "Hemi"

Tomguy,

Go to http://www.whnet.com/4x4/oil.html for a complete list of MB approved oils for your car. (You can't go wrong following the manufacturer's recommendations!)

The findings listed there may surprise you:
"...some oils which are not recommended:
Mobil 1 SuperSyn 0W-30 SL/SJ/CF A1/B1/A5 9.7 doesn't meet 229.1 nor ACEA A2 or A3
Mobil 1 SuperSyn 5W-30 SL/SJ/CF A1/B1/A5 9.8 doesn't meet 229.1 nor ACEA A2 or A3
Mobil 1 SuperSyn 10W-30 SL/SJ/CF A1/B1/A5 10.1 doesn't meet 229.1 nor ACEA A2 or A3
These 3 oils do not meet MB spec of > 3.5 cP for high temperature high shear strength."

You will find very few xxW30 weight oils that are approved.

Personally, I find 3000 mile changes to be a total waste of good oil, as the additives of today can easily go two or three times that and more. If you really want to know, start doing oil sampling and see real facts for yourself rather than taking someone's opinion.

Gerry

The Mobil website suggests either 5w30 or 10w30 for my Jeep, depending on what temperature I put on the chart.
I used 5w30 for the winter - considering the Jeep is never garaged and I usually only drive it to work in the harshest weather (ice cold temps less than 20F, snow etc). I have no leaks, and I am only about 0.5q low after 1200 miles. I'd never put 5w30 in if I didn't have faith in my engine for it to not burn it like gas, or blow it by every seal (since I maintain the vehicle quite well). For my Chrysler, the Mobil 1 site recommends 10w30 - and that's what I used in it. It's also what the manual calls for. If I try a 2007 Chrysler 300 Limited (same engine) it still says 10w30. Now, if you can tell me why 10w40 is better for either one than the oils I put in, I might change viscosities. But I will not put a dino oil in my engines!

__________________
Current:
1999 Chrysler 300M - 211,xxx
2014 Jeep Grand Cherokee Limited - 61,xxx

My Mercedes Benz 108 and 109 resource site

Previous:
1972 280SE 4.5 1992 Jeep Cherokee Laredo "Jeepy"
2006 Charger R/T "Hemi"