Regular or Synthetic

I'm looking for some advice for my 1998 100hp Mariner. I just bought the boat and the previous owner was using regular oil. I have a chance to purchase full synthetic for really cheap. Should I switch over? Will this older motor benifit from synthetic? or should I stick to regular? Thanks
(I did do a search and nothing until I posted my thread, so go easy please)

Re: Regular or Synthetic

Do whatever you feel is best. It's a personal decision. I don't run synthetic in my boat because the oil is changed so often based on hours of run time between oil changes.

Others will tell you synthetic is the way to go, someone will likely chime in ans say the Amsoil is best. Next thing you know there is so much conflicting advice that you will be no better off then before you asked the question.

This is how oil threads go around here, I'm not trying to be a jerk towards you. I just thought if I made a summery of how oil threads go it would save some time.

Re: Regular or Synthetic

If the oil is "rated" for use in your engine and the price is right, use it. Synthetic oil in a two stroke generally results in less smoke and is slightly better for the environment. Other than that, all you will get is "claims" of better performance with no real supporting data.

Re: Regular or Synthetic

Silvertip said:

If the oil is "rated" for use in your engine and the price is right, use it. Synthetic oil in a two stroke generally results in less smoke and is slightly better for the environment. Other than that, all you will get is "claims" of better performance with no real supporting data.

Click to expand...

I assumed we were talking about a 4 stroke application. Do you mean the premix oil for a 2 stroke?

Re: Regular or Synthetic

My apologies. I looked up the motor and its a 2 stroke. Disregard my earlier post.

Re: Regular or Synthetic

Let me hyjack this thread a bit. This year I have been flying off West marine biodegradeable Full synthetic TCW-III 2 cycle oil ($40/gal) against the Wallyworld dino TCW-III ($12/gal). I have one kind in each boat, and have been using both boats and trying to characterize the differences.

So far the conclusions are less than black and white. The Wallyworld oil may (may) smoke a bit more, but not a lot more, and it does have a slightly nastier smell. The question is whether the benefits of the synthetic is worth 3 times the price.

At this point for me, I do not think I will spend the extra $$ for the Synthetic oil in the future.

Re: Regular or Synthetic

Thanks for the replys. My only concern is the motor being older and weather or not synthetic would be ok to use? The price point that i'm getting is cheaper than a brand name regular. Thanks.

Re: Regular or Synthetic

I actually had a guy tell me that they didn't make synthetic oil when my motor was made, therefore he wouldn't use it. That in my opinion was just uninformed babble.

I have owned 2 stroke dirtbikes for years, I used to use Golden Spectro blended oil, it smoked like crazy, I fouled an occasional plug, and blew oil all over my fellow riders that were behind me, the stained riding shirts didn't lie. I rode a Honda CR500 and a Kawasaki KX500 and I tore them down and maintained them myself. I checked the cylinder bore each time, and every couple of years replaced the piston only due to fatigue at the bottom of the piston skirt. I can tell you without question that my cylinder wear dropped to almost nothing after switching to Amsoil, I threw less smoke, I fouled NO plugs, and my riding buddies no longer got spladdered!

The supposed difference in Dino vs synthetic is that synthetic seeks heat, dino runs from heat. Friction causes heat, I want my lube going to where it is needed. +1 for synthetic and especially Amsoil.

Re: Regular or Synthetic

I would offer that it should be fine as the oil properties should all be to standard for each grade, no matter how old the engine is, you should be fine.
I use synthetic in all my motorized equipment and I have not had any oil/wear issues in any of them.
00 Dakota, 04 F-150, 85 Ramcharger and 05 Montana, Polaris snowmobiles and Mercury outboards.

Re: Regular or Synthetic

Gee Hotrod, Amsoil is not rated TWC-III. If it were me, I would not use it or recommend it, based upon your one data point.

Also, I have some experience with 2 cycle dirt bikes. Never have I seen liquid oil expelled in sufficient quantity to foul someone's shirt. Was your oil pump adjusted properly(if you had one)? Was the premix ratio (if applicable) correct?

Do you have any analysis for your final statement about synthetic oil "seeking" heat...or dino oil "running" from heat? So you say your Amsoil "knows" where it needs to lubricate. That is some smart oil. Can you back that up?

Re: Regular or Synthetic

Ive read alot of statistics on the perceived benefits of syn over dino , and I use syn myself in most applications. However I dont recall ever hearing the [ seeks heat claim] Please elaborate, my curiosity is aroused as well ... Thanks PTJ

Re: Regular or Synthetic

I've been using WallyWorld dino outboard motor oil for 25 years in my Yamaha 115 hp 2 stroke, and it still runs great. I don't see any reason to spend the extra $ if it's performed as the specs.

I also use it in my 1990 Sea Doo, and the head was very clean last time I pulled it for de-carbonizing.

Otherwise, I would be using Pennzoil dino outboard motor oil.

Last time I had a Sea Doo XP, it required special SeaDoo synthetic oil. My dealer suggested Amsoil as a cheaper alternative, and it also gave great service.

Re: Regular or Synthetic

In my cars with new or rebuilt engines, I use amsoil. At oil changes only a couple times per year, I spring for the good stuff. Whether or not it makes that much difference in the long run, I can't say.

In my outboard, I feed it the el cheapo dino oil. Mine's an early 80's premix motor so it's gonna run a little more smokey no matter what. Also in the past I've tried running synthetic 2-stroke oil in a 70's motor and it made it run funny (mis-firing, down on power) until I switched it back to the dino oil. So I've just stuck with the cheap stuff ever since.

Re: Regular or Synthetic

Hey 444, is the Amsoil rated for automobile use? Last I saw modern motor oil had an SF or SG rating. Has it received that rating?

Re: Regular or Synthetic

Chris1956, with all due respect to your rank, and I mean that seriously, I have seen the demonstration where they put a torch under a steel plate and pour Dino vs Amsoil and Amsoil will migrate towards the heat and vise versa with the Dino. Is that Scientific enough, maybe not. Amsoil does say "Recommended for pre-mix use where TC-W3 or API TC is specified" which as you correctly point out, is not the same as saying it on the bottle. I have to recall a quote from the movie Tommy Boy, "if you want me to take a dump in a box and mark it guaranteed, I can do that, I've got the time"........... LOL, but in all seriousness, I get your point and I can only go by what I have experienced in the past. Discussing Dino vs Synthetic is one of those topics like discussing religion or politics with a friend.

As far as my comments about oil splattering, I was running 20:1 of Golden Spectro and at one time, BG 2 stroke premix in both my KX500 and CR500, both with the same results, black riding clothes on my fellow riders. Keep in mind that both of these bikes could also shoot 3' flames out the back if they backfire, I have personally experienced both. It also fouled the packing much more frequently in the silencer.

Re: Regular or Synthetic

Hotrod, I will assume the demo was performed by Amsoil? If there is an analysis why heat migration occurs with synthetic oil, and the benefits of such a migration, great. If no analysis of that kind, then it is advertising pure and simple.

As an example, BRP paid some advertising firm to advertise that a DI 2 cycle outboard motor was better for the environment than 4 cycle FI motors. Their advertising stated that it was better for the environment to burn 2 cycle DI oil in the e-TEC motors, and dump the vapors and smoke into the water than to run a 4 cycle outboard, because 1/3 (or some percentage) of all 4 cycle oil is improperly recycled. There premise was that the burned DI oil was less polution than the illegally dumped 4 cycle oil. Is this true? Who knows, but it will obviously convince folks to buy a e-TEC, which is the point of advertising.

I try to stay clear of recommending things that are not considered standard practices. I will recommend TCW-III 2 cycle oil, because it is certified under standards. I do not recommend products that have claims that are not substantiated (think oil additives, gas additives, transmission additives, tablets that you toss into cylinders to fix bad rings, devices that boost MPG using screens between carb and manifold, and other such snakeoil or unproven devices).

You may recommend what you like, however, there are some folks who depend on our advice, do not have a lot of experience and I would not like to think I led them down a wrong path.

Re: Regular or Synthetic

BZZZzzzzzz* snort, kaff, bzzzzzz.:facepalm:

Re: Regular or Synthetic

Well apparently I hit it on the head when I posted how oil threads go. I just didn't realize that oil threads for 2 strokes go exactly like iol threads for 4 strokes.

Re: Regular or Synthetic

Thanks again everyone. I will be doing the switch once I burn off the rest of the regular oil. By the way, the oil I can get is Shell Nautilus Full Synthetic for less than $4\litre. Any thoughts on Shell?

Re: Regular or Synthetic

[ Any thoughts on Shell?[/QUOTE]

I think they are a Dutch company.