Trojan Boat Forum

What brand and weight does everybody use ??

Any opinions on Synthetic ??

Use wolfhead 15-40 syn-dino blend, use it in my boat,gmc,and my FedEx trucks never had any trouble with it.

15w-40 100% dino Shell Rotella , I have used 15w-40 in the last 4 boats I have had. I buy 10-12 cases at a time , Getting ready to buy again so may switch brand depending on price , but will be a name brand.


Would not pay a dime more for Synthetic so I don't use it .

If you have high hours on the engines I personally would stay away from synthetic oil. I have seen synthetic oil wash out carbon build ups that would end up in a loss of oil pressure. Basically it 'WASHED' the engine clean. If you have less than 400hrs on the engines then I would consider it if all oil changes have been done faithfully. On new engines I wouldn't hesitate to use synthetic. But thats my opinion, an you know what they say about opinions, there just like a##$$%%*

Rotella straight 30

MTP wrote:Rotella straight 30

+1 that's what Cat calls for well the straight 30 part anyway.

I use Shell 15w-40 in my Mercs and change it every year no matter how many hours I use the boat for the year. This year I only ran it for about 8 hours but it was still changed when I hauled it out.

Allen Sr wrote:If you have high hours on the engines I personally would stay away from synthetic oil. I have seen synthetic oil wash out carbon build ups that would end up in a loss of oil pressure.

39 years working on engines for a living and that is a new one on me . I am not a big fan of synthetic oils and would only use them if the OEM calls for it But I can tell you that would never happen , there was/is a fear the changing to a synthetic with high miles/hours could cause seal leaks but that maybe a thing of the past . I have seen many switch no issues but have not seen any gains also .

The most important thing is to change it as recomended by the Engine maker .

Opinions?.... everyone has one and most of them stink. Is that what you're trying to say Allen Sr? I use Mobil one in my Cadillac CTS-V because the factory says to but I have had two bad experiences with synth in older motors and will not do it again. The first time I thought it was a coinkedink but after the second time I quit using synth. The engines still ran ok but they immediately developed a knock that sounds like a wrist pin or similar when cold. 10-40 has been working just great and if it aint broke don't fix it.

MTP wrote:Rotella straight 30

Yup. By they gallon.

15W-40 changed at end of every season. Engine is stock 77 and only work done on it tuneups and carb rebuilds. But then again I'm old and stuck in my ways, and so is the boat.

A customer (ham & egger) in '08 demanded I change his oil over to mobil 1 on his 8.1s. He told me this summer that he has to add a 1/2 qt. of oil to each engine every month now. Engines had 670 hours on them in '08

Royal Purple 15W-40 after break in, works fine for me. I change every 40hrs.

Is he still changing like he should ?

prowlersfish wrote:Is he still changing like he should ?

As far as I know he is. He started doing his own work on the boat end of '08