Is Royal Purple too much for older Mercedes Benz??

Too much of what? If you over-fill it, then yes, you used too much.

__________________
'98 E300 turbodiesel

Nah, you can use Royal Purple if you'd like. I was a diehard Royal Purple guy, but the latest I read was the Royal Purple is still using the same old formula, but Mobil1 has been making theirs better. With RP costing almost $9.00 a qt and M1 costing $7.80 a qt, I switched to Mobil1.

__________________
- Brian


1989 500SEL Euro
1966 250SE Cabriolet
1958 BMW Isetta 600

Royal Purple has never bothered to have their oil Mercedes-certified, meaning they don't care about Mercedes and meaning it's "not enough" for a Mercedes.

__________________
Kent Christensen
Albuquerque
'07 GL320CDI, '10 CL550. '01 Porsche Boxster
Two BMW motorcycles

Although the first part of your statement is true, the last (two) parts are just speculation. Has anyone asked RP why they aren't tested for use in MB cars?

__________________
Steve A
92 W140 OM603
97 VW Jetta TDI
90 Passat variant TDI 6 speed MT
94 Chevy K1500 6.5TD
05 E320 CDI
+ others

For your M103, stick with 15-40 Diesel oil Rotella-T. It is the best choice hands down. Keep change intervals every 5k and you'll have a long lasting, clean valvetrain. You'll also save a lot more money. $9/qt is ridiculous. Rotella-T is roughly $12/gallon which works out to be $3/qt

__________________
2016 Monsoon Gray Audi Allroad - 21k
2008 Black Mercedes E350 4Matic Sport - 131k
2014 Jeep Wranger Unlimited Sahara - 62k
2003 Gray Mercedes ML350 - 122k

I am not a fan of Royal Purple. It is a completely different formulation than all other oils. The main difference, and the reason for the 'purple' colour, is the very high molybdenum content. Great on paper and static tests but the resultant high solids content means it quickly drops out of solution rendering the product less effective. Over time much less effective.
Great for race engines. Not street cars.

__________________
I don't know the same things that you don't know.

Shayne

85 W126 SD OM617.951
87 409D 650S OM617.913
93 E34 Touring M50B25TU
02 E46 Sport M54B30TU

The reason for the purple color is marketing.

__________________
Kent Christensen
Albuquerque
'07 GL320CDI, '10 CL550. '01 Porsche Boxster
Two BMW motorcycles

I stand corrected. The purple is dye.

__________________
I don't know the same things that you don't know.

Shayne

85 W126 SD OM617.951
87 409D 650S OM617.913
93 E34 Touring M50B25TU
02 E46 Sport M54B30TU

Any adverse effects if you switch to Rotella T from Valvoline maxlife?

__________________
Streetside: 1987 Mercedes 300E Petrol Blue/Green
2014 Ford Mustang Grabber Blue
1999 Ford Ranger Green

Dockside: 1968 Eltro 17
1985 Silverton 34C

There are no detrimental affects from switching from any motor oil to another correctly rated, quality motor oil. Ever. Contrary to some opinion you can also go from synthetic to dino and back with no ill results.

__________________
I don't know the same things that you don't know.

Shayne

85 W126 SD OM617.951
87 409D 650S OM617.913
93 E34 Touring M50B25TU
02 E46 Sport M54B30TU

I have been running Castrol full synthetic 10W-40 year round in this Mercedes since I purchased it. The previous original owner used dyno in it. I like the way the synthetic has done. It is very quiet, and no big contamination or wear indications. I was just thinking if the Royal Purple was much more enhanced, that I would bump the bar. Also, if it gave better protection on some of the rubber and plastic internals it might be worth the investment. Thanks, for the information on it!