Oil grade

"Volvo keeps changing the part

"Volvo keeps changing the part number of the oil for my engine. Its a 1993 740B. The latest number I have is 3809433, but the local marinas are no longer carrying it. They have the new "Gasoline Engine Oil" 3847302, and it says it is conventional motor oil. I am afaraid of changing from a synthetic blend back to a multi grade conventional. I've heard that you should never back up to non-synthetic. Should I do with the recomended oil or go with the full synthetic? The auto parts stores I called don't carry a 20W50 synthetic blend, otherwise I would just get a different brand."

"I found Valvoline SAE 20W-50

"I found Valvoline SAE 20W-50 MaxLife synthetic blend motor oil in stock at a Autozone, its not local but not to bad of a drive. , Any opinions on Valvoline as a substitution? Or they also have Valvoline SAE 20W-50 SynPower full synthetic motor oil, should
i be switching to a full synthetic? In which case should I stick with volvo and swith to Volvo's 30 weight full synthetic?"

"The original spec for your en

"The original spec for your engine calls for SAE20W/50 engine oil, service SG. It does not specify it has to be synthetic or synthetic blend.

http://vppneuapps.volvo.com/ww/PIE/ViewFileFrame.aspx?n=197812&r=2008-10-22-13-3 2-07&t=PDF&a=7749423&p=T403&d=OwnersPublication&s=7114009&lang=en-GB

IMO, any oil meeting or exceeding the above specifications will work fine on your engine, regardless of the oil being mineral, semi-synthetic, or fully synthetic.

There are a lot of urban legends regarding switching from mineral to synthetic and vice versa. The fact of the matter is that both types of oils can be mixed with no problems (as an example, a "synthetic blend" is a mixture of synthetic and mineral oils). But if you want peace of mind, you may want to stick to an oil grade & type that has given you good results, regardless of which company manufactures that oil.

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"I found your statements about

"I found your statements about it being a urban legend also on valvoline's web site. I quess my concern is that Volvo keeps changing the grade and type. I quess I'll folow your advise and stay with the 20W50 synthetic blend and it was what was on board when I bought the boat, and it is what I have always used. Thanks for your input."

"I always use the merc oil sin

"I always use the merc oil since its a little cheaper, my 8.1 g.m. engine is the same as my friends who have the merc outdrive"

"It’s always a good idea to st

"It’s always a good idea to stick with the same brand of oil that has always been used in an engine. (As long as it is good quality oil) Different brands of oil use different detergents. The detergent in one particular brand of oil may remove certain particles in the engine, where another brand of oil may remove other types of particles in an engine.
I changed brands of oil in an older engine that had been well maintained one time. Particles that had built up in the engine were washed loose and clogged the lifters.

G"