Extending OCI (a little) on dino

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5,763
Location
Da Swamp
Hello, all, I've been an enthusiastic learner here for a while, and I know that a lot of variables affect one's engine and choice of OCI. I'd like to extend mine a little. Here's the deal: Car: '97 MB C230, normally-aspirated 4-cyl.; does not require synthetic oil. Commute: about 9 miles to work. Approximately 5 of those miles are done at 50-60 mph; the rest at 35-40, with a few stoplights. I do the same 9 miles back home, but most of the 5-mile 55 mph run is bumper-to-bumper traffic, with speed averaging about 20-25 mph. On the weekends, I do a lot of short-trip driving, groceries, car wash, etc. I try to get in a 10-15 mile freeway drive two or three times a month. My total mileage for a month averages about 800-900. (There's not many places to go here in The Swamp.) Right now I'm doing 4 months/3200 to 3600 miles between changes. Oil is usually Delo 15W-40 thinned with a little 5W-30 Havoline; now and then, TropArtic 10W-30 syn blend. I realize modern dinos can go longer, but with my short-trip setup and near-severe service, I'm uncertain. Would five months/4000 to 4500 miles be OK? Generally, what would be a reasonable OCI? -- Paul W.
 
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5,785
Location
Dixie
I'd consider a 0w-30 synthetic and tripling your OCI's. You'll do significantly better in terms of fuel efficiency and still get excellent wear protection. The Amsoil Series 2000 or the German Castrol 0w-30 should both last that long. Another good choice would be the Mobil 1, 0w-40. TS
 
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8,711
Location
Nothern USA
On Monday morning, 9 miles of traffic should boil off any fuel and water that may have built up over the weekend. I think you could go with the ''normal'' schedule. What is the recommended weight of oil? Unless it is 15W-, I would switch to a 5W or 10W dino or the 0W synthetic suggested to give better protection on all the start ups. I do a lot of short trips and like the 5W-30 dino I use. Of course, I have a considerably colder climate.
 
Messages
8,711
Location
Nothern USA
The Pontiac Phoenix I had, sludged up on 6 month OCI's running QS SF. After I traded it on a 92 Grand Am, the owners' manual was very explicit about running 3 month/3K oil changes for short trips as does the manual for the 02 Cavalier I have now. I have also treated my 77 LUV to the same 3 month OCI's since then. With both now out of warranty, I have considered longer OCI's backed by a UOA. Perhaps you should do a UOA at you next oil change. You would then be able to make a decision with more data than the others and I have. Back when I switched to 3 month OCI's, I could still catch AC filters 2 for $5 at K-Mart and Pennzoil 5W-30 was less than a buck a quart. At today's prices and quality of oil, I am rethinking some of this stuff.
 
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11,664
Location
Illinois
I think I'd keep doing what you are doing. Three changes a year, every 3-4K miles is probably good. I'd add a longer drive EVERY weekend. Maybe 30 minutes or more. Why not get a UOA from the next change analyzed and see how much life is left to determine how long you can expect to go?
 

KW

Messages
1,686
Location
Central Arkansas
Rottela T 5W40 group III twice a year should do the trick for you. For better fuel economy Tooslick's reommendation of 0W30 or 0W40 is a good one.
 
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1,203
Location
Oregon
quote:
Right now I'm doing 4 months/3200 to 3600 miles between changes. Oil is usually Delo 15W-40 thinned with a little 5W-30 Havoline; now and then, TropArtic 10W-30 syn blend. I realize modern dinos can go longer, but with my short-trip setup and near-severe service, I'm uncertain.
If it was mine I would treat it like a severe service also and keep doing what you have been doing.
 

Benzadmiral

Thread starter
Messages
5,763
Location
Da Swamp
Labman, That's what concerns me, the buildup of moisture, acids, and fuel from the short-tripping. I should mention that the 9 miles takes around 1/2 hour, so the car isn't just puttering along for 10-12 minutes or something. The recommended weight for the Benz isn't listed in my owner's manual. It just says to ask the dealer (!). The "Recommended Fluids" supplement has the standard (for 1997) temp/viscosity chart, and any of the usual weights (5, 10, 15) are fine depending on what temp you expect to see before the next change. Just to make it more complicated (CAFE vs. Rest of World?), my Haynes UK manual recommends 10W-40 to 15W-50, with OCIs of 10,000 km (6200 miles). .
 
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