5-30 or 10-30 Mobil 1

[MinUph]

Whats the consensus on running 5-30w or 10-30w Mobil 1 in a 1999 40hp Honda? I read that there is little difference between the two and running 10-30w in an older motor might be OK. My manual states 5-30w but the last owner was running 10-30w in it.
Living in Florida where the gulf temp reaches 85 90 degrees I wonder if it matters.

 

[hondon]

Re: 5-30 or 10-30 Mobil 1

Here we go with the whole synthetic oil debate again.Honda has never fallen all over themsevles reccomending synthetic oils only because they would rather you stuck to the service intervals and these oils have not met thier standards for water intrusion.Since you are in those water temp conditions 10w 30 would be the logical choice ,synthetic or blended.

 

[JB]

Re: 5-30 or 10-30 Mobil 1

We get a lot of inquiries asking if it is okay to do something different that what the Manual or later tech bulletins tell us to do.

The Manual says 5-30w. There may be folks that are smarter than the guys who designed and built the engine, but it isn't really likely. The temperature of the water has very little effect on the operating temperature of the engine.

While I have the greatest respect for Hondon's judgement, I would ask Honda what to do, and follow their instructions. They may tell you to avoid synthetics altogether.

 

[MinUph]

Re: 5-30 or 10-30 Mobil 1

JB,
I thought about that myself. Just go to normal oil like it recommends in the manual. Seems like the logical thing to do as I normally follow recommendations given by manufactures for just the reasoning you mention. I wonder if there is any issue switching back to regular oil after the motor had been used with synthetics.
Some sort of oil goes in tomorrow so I will have to make up my mine by then. I'm leaning towards standard oil in the 5-30w range as noted in the motors manual.

 

[DanMC]

Re: 5-30 or 10-30 Mobil 1

hondon, MinUph did not even mention synthetics....
Dan

 

[hondon]

Re: 5-30 or 10-30 Mobil 1

Honda offers both 5w-30 and 10w-30 as off the shelf options.Since you are in a warm climate the 5w is hardly nessesary but wo'nt hurt.5w gives you the adequate thinness to aid in starting in cold external temperatures.That mutiviscosity rating is designated by SAE and means that at a certain temp it will act like a 5w or 10w and at the higher temp will act like a 30w.

 

[MinUph]

Re: 5-30 or 10-30 Mobil 1

Big decision made and went with normal Pennzoil 5w30. Changed the filter and oil. Were done here Thanks for the input.