posted 02-27-2004 09:56 PM ET (US)        

I would have to think that it couldn't hurt, and it just might be better [than the recommeded oils]. I don't know in a marine application such as a 4-stroke outboard [if my supposition that synthetic would be better than the recommend manufacturer's oil would be valid]. I run Mobil-1 in all my cars. Is there any reason to not do the same with my new F200?

posted 02-28-2004 12:59 AM ET (US)            

Honda recommends API service category with the "starburst" certification mark displayed on the container.

posted 02-28-2004 08:55 AM ET (US)            

The notion that it might be inferior to petro-lubes (except for break-in) never occurred to me, and still doesn't.

I did use the oil supplied by my dealer for break in on the theory that a "too-good" lubricant might retard seating of rings, etc.

Quite a few Yamaha and Mercury 4 strokes experienced gas-in-oil syndrome, partially from incomplete seating of rings on break-in and partially from running too cool (read rich). One might speculate that use of superior, fully synthetic, lubricants during break-in could have been a contributor.

Mercedes Benz insists that I use Mobil 1 in my ML. I insist on it in my Suzuki.

posted 02-28-2004 10:12 AM ET (US)            

Point of clarification…I would not be changing the recommended viscosity…just simply going from a dino-oil to a full synthetic. The Yami manual does give a range of recommended viscosity’s but that is dependant on the environment in which you will be using the motor (similar to what you see in your cars manual).

As for break-in that’s just my $.02 in that with countless cars it has been recommended to me to not use full synthetic during break-in in order to allow all the internals to seat properly. Now there are a few cars such as the Z06 (and a few Porsche’s I believe) that come straight from the factory with Mobil 1…so maybe that’s not true.

posted 02-28-2004 06:56 PM ET (US)            

Mercedes delivered my ML with Mobil1 in it, so they seem to have no concerns about seating rings, etc. during break-in.

The reason they give me for requiring full synthetic oil is the computerized oil condition evaluation that schedules oil changes based on real-time analyses of the oil. In 123,000 miles it has called for a change in as little as 3,000 miles (short trips, city driving) and as long as 13,000 miles of long trips at cruise speeds.

Without that unique sensor in the crankcase and the computer to compute condition, I wouldn't alter the change cycle.

posted 02-28-2004 10:01 PM ET (US)            

By requiring synthetics and using these "common sense" data, MB insures itself from premature oil break down, excesive drive train wear and therefore short engine life or worse, oil consumption before warranty has expired. In the USA with the magnificent road and highway system the distances driven daily in most cases might exceed 16 miles per cycle (distance between starting and stoping the engine before it reaches operating temperature) and this helps conserve the oil free of combustion byproducts and good filtration will keep carbon and metals from causing excessive friction.

In very cold temperatures the motor might take longer to warm up, this will throw a flag and shorten the oil change interval, in towing conditions the computer might record higher than average coolant temperatures even oil temperatures if it has such an oil temperature sensor and throw in a flag that might also shorten the oil change interval. All else the computer might conclude that the conditions are ideal and increase the oil change and filter interval.

But I believe that in none of the above conditions JB runs his MB's drivetrain at 4,500 rpm to 5,500 rpm under load most of the time, like you might do with your outboard. I am a fan of synthetics in my car as I believe that I am postponing his drivetrain's demise, however, my GMC Jimmy seldomly sees 2,500 rpm even in our mountainous country and I replace the oil and filter and other lubricants at 1/2 the manufacturer's recommendation as an extra meassure of precaution. However, my outboard is almost always used at 4,500 rpms since I have not mastered trolling yet, in very humid conditions, perhaps at temperatures that could promote condensation inside the crankcase, with sulphurous fuels, etc. I would call the latter conditions extra severe.

posted 02-29-2004 06:36 PM ET (US)            

The ML has a sensor in the crankcase that measures oil conductivity in real time.

The firmware that calculates the change interval calculates miles remaining to recommended change based on:

Engine hours.
Vehicle speed.
Coolant temp.
Load signal.
Engine rpm.
Engine oil temp.
Engine oil correction factor (conductivity).
Engine oil level.

My MB Service Training Manual assures me that If I ever need to add oil (not yet in 123,000 miles) the calculated interval will be extended by the change in conductivity sensed on the next running of the engine.

Perhaps my use of the term "analysis" to avoid a 300 word explanation was oversimplification. Nevertheless, I consider measuring conductivity an analysis, as every oil condition factor you mentioned affects oil conductivity.

I see no reason why a similar sensor and program wouldn't be suitable for a 4 stroke outboard.

posted 03-01-2004 04:13 PM ET (US)            

At the time I purchased the initial pickup ('76) I called GM and asked their thoughts and comments - no problem, no impact on the warranty, et.cl.

But, as one mentioned, I would recommend breaking in with the manufacturer's break-in oil and then change to Mobil 1.

In the '70's and 80's, some manufacturer's seals would not hold Mobil 1 all that well. I suspect that has changed by today.

Mobil 1 recommended (years ago) to drive the vehicle for 50,000 miles and then change oil and filter. Instead, I would run until I was down a quart (about 6,000 miles) and then change filter and add two quarts of oil. When that engine was changed and inspected, the engine showed virtually no wear - commendable! Today, I am doing the same thing in a Buick LaSabre and another GMC 3/4 ton pickup. ----- Jerry/Idaho

posted 03-02-2004 10:19 PM ET (US)            

Thanks for the ample clarification! Indeed the MB has a sophisticated oil analysis system and your MB's millage and no oil consumption show how much of a close tolerance motor your car has!

But how do automotive situations compare to boating situations? Aren't outboards used under load all the time even at part throttle? Are these 4 stroke motors built under the same close tolerance as the automotive motors? Could such a close tolerance motor survive 500 hours under load all the time?

I would like to learn more on these recommendations from the 4-stroke manufacturers...but I would also be interested in learing more on the life cycle of such a 4 stroke motor also.

I do trust Mobil 1. I have used it in most of my cars including my former 250,000 Km Honda Civic, but after performing oil analysis when the car was almost new, the lab recommended changing the oil and filter every 5,000 Km, sample after sample done at 5,000 Km change interval and at $6 per liter it is a matter of blind faith to keep using it. Perhaps my Honda was not built as a MB.

By the way Mobil does recommend using Mobil 1 as soon as possible, even before "break in" is done.