I was going through some old MB texts that they gave with the car when new and I ran across the recommended fluids sheet. It showed that Mobil1 15w50 is a year round oil while Mobil1 5w30 should only be used below 30F. I'm outside of Chicago and an thinking of switching over to Mobil1 15w50 for year round use. It is an 1988 300E with 105000miles. Is there anybody else out there in similar climate who is also using this oil. If so your input is greatly appreciated.
Thanks,
Dino

Sorry let me clarify
"Mobil1 5w30 for temps below 30C / 86F
Mobil1 15w50 for use all year"

I've used 20W50 in the Chicago winter before changing over to 10W40. With 20W50 I found that it turned over slower in freezing temperatures. Once up to temperature it seemed to do well. With 10W40 I found that on short trips in freezing temperatures that a white sludge would build-up (under the oil cap). Once the car reached normal operating temperature the white sludge would "dissolve".

Since Mercedes recommended synthetic oil for 1998 and newer vehicles I've been using Mobil 1 15W50 for the summer and Mobil 1 0W40 for the winter. The advertisement on the Mobil 1 0W40 container states "Superior sludge and wear protection under severe, short trip operation". Time will tell on how it performs this winter.

Before Mercedes recommended synthetic oil for 1998 and newer vehicles, a local Mercedes dealer (Chicago area) said that they use 10W40 weight oil for the winter.

From the posts I've read Mobil 1 0W40 is the year round oil.

You might want to check out the Mobil 1 web site: www.mobil1.com for the stats on their various weights.

__________________
Ray
1998 Mercedes E320, 200K Miles
2001 Acura 3.2TL, 178K Miles
1992 Chevy Astro, 205K Miles

Dowxz,

I have used Mobil 1, 15W-50 year round in all my cars with no starting or other problems for the last few years. I am presently looking to put Mobil Delvac 1, which is a 5W-40 grade, in my Diesels based on the information I have gleaned from this site, but only because it is specifically constructed for dealing with the Diesel combustion products that make the oil black in a few minutes of operation. I will continue to run 15W-50 grade Mobil 1 in my gas cars.

I am about to turn in the C230 Kompressor/Sport at the end of its lease and pick up a 1988 300E with a manual transmission, just under 100K miles. I will convert all of its lubricants to synthetics (I like using Redline's transmission and differential lubricants), and will likely run 15W-50 Mobil 1 in that car as well.

I do not see the same sustained cold weather you do, however. I live on the Long Island Sound shoreline in Connecticut, and we get relatively few periods of below 20 degrees Fahrenheit that last for more than a few days. In your climate I might consider the 0W-40 grade if it was available. I have yet to see it on a Mobil station shelf, or in Walmart, Target, PepBoys or Autozone. Since the 0W-40 is an all year blend as well, I would leave it in all year unless I experienced some kind of problem I could attribute to the change in oil grade. I really only picked the 15W-50 because it was available and covered the temperature range I drive in, and have continued to use it because it works well.

Hope this helps you. Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

Dino,

If the Mobil 1 0W-40 is available in your area (I thought I saw a post where it's available near you), I'd go with that year-round in your '88 300E. Otherwise, I'd go with the 5W-30 in the winter and switch to 15W-50 in the summer.

Ten years ago we had a doozy of a winter here and I ran 15W-50 in my car for the first 3 months of, what seemed like, a 9 month winter. I did notice a noticable reduction in cranking speed. So unless you have an oil consumption problem, I'd leave the 15W-50 oil for the warmer months.

Bill