Another oil thread

[jward]

I have never really read up on oil. I pretty much just put in what is recommended for the engine I am servicing. I was buying 15W 40 for my 210 and was reading the back and noticed that this oil is primarily for diesel engines. It does say also for gasoline engines. My question is why would pcm call for this oil? I'm sure some of you engine guru's will have plenty of input. I tried google searching but didn't find much.

[gride]

not totally sure why, but that's what most, including myself, use. shell rotella t 15w40.

[TRDon]

I had a heck of a time with this myself last week. My first oil change on my EXCAL330 and I didnt know what to use. I know the 15-40 was recommended, but all I could find was diesel oil and stuff loaded with zinc which I dont need because it is a roller cam motor. The best I could find through my research was people on here have gone with the 15-40 but others have used 10-40 or the mobil1 15-50.

I looked up what the numbers meant and it is a flow rating. The first number is the flow rating when cold, and the second was flow rating at operating temperature of 212*f. I figured that the better flow cold of a 10-40 would be nice for startup and quicker oil distribution while warming up and the 40 will still be what is recommended from the original 15-40 PCM asks for.

I ended up going with a conventional valvoline 10-40 for that reason. I would have gotten it in the standard Mobil1, but they dont have it. There was something like a high mileage or something mobil1, but I didnt want any additives I dont need for an engine with so few hours.

[shag]

I use Mobil 1 full synthetic in everything. I just had the dealer put it in my 09' SAN/excal. 330

[jward]

I copied and pasted straight from the manual.



Synthetic Oils
Synthetic engine oils are not recommended for use in PCM Engines. Synthetics may offer advantages in cold temperature pumpability and high temperature oxidation-resistance. However, synthetic oils have not proven to provide operational or economic benefits over conventional petroleum-based oils in PCM Engines. Their use does not permit the extension of oil change intervals.

[shag]

I understand the PCM statement. But it only states that 'they' don't see any added benefit buy using it. 'I' have used it in any engine powered vehicle/boat I have owned since the early to mid eighties and have had 0 (knocking on wood) problems. My .02

[TRDon]

what the book says is they see no econimic benefit because you dont extend oil changes. I never have on anything I own either. I change at every 3-4000 miles on my car, truck, every 50 hours on my boat and lawnmower and every 1500 on my mustang that sees hard miles and tons of heat from a supercharger. All I own uses mobil1 except the boat. If mobil1 had a 15-40 or a 10-40, I would run it in that too, but they dont. The manual even recognises there are benefits to startups and thermal breakdown properties of a synthetic, but states there is no benefit in PCM engines based on econimic benefits. I guess I really dont care about paying 23.00 ofr 5 qts of synthetic vs 11.50 for conventional for the once, maybe twice a year I change oil in the boat (or would if I could get it). If that is the extent of the economic limitation they see, it really is peanuts for knowing I got better startup protection and better tesistance to hermal breakdown in an engine that runs higher RPM and high load all the time. I wouldnt think twice about what the book says unless it said any real significant reason for why not to use it, but the benefits outweigh the negatives IMHO.

[robertsmcfarland]

PCM now states that synthetic oils are fine to use as long as they meet PCM oil requirements and one does not go passed the 50 hours oil change recommendation by PCM.

[shag]

Well put TrDon. I agree, the marine engine lives a hard life, and I believe that Synthetic gives those added benefits you mention. The one oil I don't understand is 'synthetic blend', Why not get 100% synthetic?

[ronskal]

PCM now states that synthetic oils are fine to use as long as they meet PCM oil requirements and one does not go passed the 50 hours oil change recommendation by PCM.

Yep, my new 210's PCM book says synthetics are OK. I am at 45 hours on my boat and will come up on my second oil change before winter layup. Even though I am a big fan of Mobil 1, run it in my tow vehicle/daily driver, I have been using conventional marine oil in my boats. I run Mercruiser 25W-40 but may convert to Mercruiser Synthetic.

The marine oils have better corrosion resistant additives which are a help for the winter layup. Diesel oils have pretty much the same spec. as marine oil so Rotella 15W-40 is a good choice also.

[shag]

I usually am pretty close to the recommended change intervals. But I pretty much change the oil when it doesn't have that golden look on the dipstick anymore, before it gets black. Black = contaminates/carbon. Am I wrong?