Can you use synthetic oil

[ted01]

in a 692? or mix with straight 40 wt? just a question. thanks Ted

[luvrbus]

DD approved synthetic oil for the 2 strokes Royal Purple was the only outfit that made a straight 40w,Cole Davenport used Royal Purple 40w in his 8v92 for years and I know some are using Amsoil 15/40 and love it good luck on this one lol

[JohnEd]

To answer the question:  Mixing works fine and some manufactures even tell you it is OK.  I think Amsoil is not one of them but visit their site and look at Purple as well.  They speak plain English in those places cause they can't count on only ESL visitors.

Once upon a time it was said that you could use 30wt syn to replace 40 wt Dinosaur.  Syn is a superior lubricant so you could push the envelope...it was said.  But look at what DD recommends and I think you will see that 30 wt is good for temperate climates as that is the spin for all other engines.  You need to look at the DD manual to see what temps the 30 wt is good for.  If it covers you then that broadens the options for syn brands....but make sure it is rated for D 2 cycle and has low ash.

Make sure you are looking at the current DD spec as those specs have changed back and forth over the years.

Syn lube in your trans and diff will pay for itself in fuel savings and those items will run 20 degrees cooler according to the trucker mags.

Trust but verify,

John

[RJ]

Ted -

IMHO, use synthetic in everything BUT the 2-stroke.

For that, stick to straight 40wt dino oil, unless you decide to spend the extra $$ for Royal Purple.

As for Amsoil 15/40, remember it's a 15 wt oil with polymers added to make it act like 40 wt.

Factory says straight 40 wt.

You choose.

FWIW & HTH. . .

[JohnEd]

Me personally?  I wouldn't use anything with 15 wt on it but there are mechanics on here that are using 15/40 and have been doing so for many years.  They think the 40 wt requirement is a joke.

If you have the all to common DD that uses a gallon every "anything under a thousand miles" then syn will put a dent in your pocket that any increase inefficiency will not recover.  And syn will run out faster.  RJ's advice is solid and well represented in the community.  But it rem,ains....syn is better.  But who cares if you can't afford it.

Thanks RJ for the perspective and reminders.

John

[Geoff]

There is always 5w-40 full syntheic Rotella diesel engine oil.  Good stuff, but for the money I would just use 15w-40 or straight 40 (if you can find it).  I'm more worried about being able to afford fuel than what oil I run.

[Lee Bradley]

Castrol makes a synthetic 40 weight but it is listed for boat two cycle DD running bunker fuel. Don't know if it can be used in diesel burners.

[TomC]

I wouldn't run synthetic in a 2 stroke-it gets expensive since 2 strokers naturally burn oil.  Keep with a good straight weight 40.  Good Luck, TomC

[eddiepotts]

I think mixing oil would be the last thing I would think about. When you loose all oil preasure and everything locks up, You will see what I am talking about. You could end up with an oil pan full of vasoline. Most synthetic oils do not mix with dino oil.I need to find the specs on our 2 stokes and send it to our Global oil specialist at Shell. He will tell me exactly what we should be useing. I just have not sat down and looked for them yet.