tellie, don't dis the Chevy Vega. Chevy had a great idea, they copied the cylinder design from Porsche and used a 210F thermostat in the Vega in order to raise the cylinder wall quench temperature by 40F and get an increased gain in performance--just like Porsche.
Except Chevy forgot, Porsche owners will spend something on maintenance
and buyers from GM's cheapest division and cheapest model aren't going to treat their cars the same. The Vega had no engine problems, it had owner abuse problems. With the Porsche cylinder design (IIRC it had something to do with a high-silicon alloy in the block, it wasn't just a temperature change) there was less tolerance for overheating
, so if the owner slacked on the coolant
or oil, poof! No engine.
On Yanmar's oil recommendations...Generally I'd take the advice of the manufacturer (excluding Westerbeke
, who are contractor/assemblers) in the belief that they also engineered the product. But aren't Yanmar the same folks who zealously protect their franchisees--yes, franchisees--by prohibiting mail order parts
sales? One might suggest that Yanmar really are trying to sell dealer service and gen-you-whine Yanmar oil and filters.
In the US there's a long history
of what engine makers say, versus what oil makers say. The oil companies took Detroit into court (in the 60s?) over the question of whether you would void your factory vehicle warranty by not using the car dealer's oil. That got changed by the courts, you can use any oil you please now and unless the car maker can prove
the oil caused an engine failure, they have to honor the warranty. Scare tactics, plain and simple.
Which is why oil makers also often will give you a written warranty against engine failure when you follow their protocols--not what the engine maker says.
Many things are best taken with a grain of salt
"Hours" is just one possible rule
of thumb. Feel the oil, smell the oil, if you think "hours" has arrived (of course your engine has a Hobbs meter, don't they all?) then send out an oil sample and get an objective report from a lab for $25. Mickey Mouse works better on the wrist than the dipstick.<G>