Onan BFA Oil - Why not 20W-50?
Note: Our typical camping climate range runs from 10F to 115F (if we go to Redding, CA in the summer... otherwise up to about 105 in Southern Oregon.) Clearly Onan/Cummins have updated their recom...
Forum Discussion
Thanks, guys!
FWIW, I'm very familiar with the BITOG site. However, I'm not looking for theory here as much as practical application.
Mex,
Good Lord! I can type 80 WPM, but you must be topping a hundred, easily! Was there an answer in there somewhere?
:)
I think I may have seen it in the "5W-30" comment.
I understand the start up wear concerns, but my motorhome is not a grocery runner. She starts and has to run for hours at a time. Same with the generator. My family are good campers. We don't start the Onan for hair dryers or microwave popcorn. We use her for the A/C and rarely to charge batteries (our rig can go a week on a single charge of the bank and we like peace and quiet in the campground. And thanks to my Mex-inspired, hot-rodded alternator, the bank is charged up again by the time we get home with or without the generator.)
I found it interesting your take on Castrol 20W-50. My father took a 1984, 4-banger 4Runner to 400K with that stuff in it year-round and sold it, still running well, for 2500 bucks. Not sure you can say start-up lubrication was a big problem there. The old hot rodder has also used STP religiously in every rig for most of his life. Oil theory doesn't seem to support that, but he has always and I mean always gotten high miles out of every rig he's ever owned and not one of them was bought new. Hard to argue with that kind of success. Did I mention the 400K mile 4-banger? With only a single timing chain job?
That Castrol is in the pan of the '86 Winnebago with 106K on 'er right now and she uses very little oil. It's the oil I was considering for the Onan, but I'm not sure the little engine that could should be seeing 50W resistance at 212F.
I do like the shorter spread of 20W-50 and 15W-40 which means they should have fewer additives than even 10W-30 and thus prone to less thermal breakdown per given heat situation.
In an effort to garner a little better mileage, I tried some Rotella T 15W-40 in the 454 and she seemed to put more strain on the fan clutch, though I cannot say this anecdote is any way scientific. She did use more oil though, so that became a one-time shot with no discernible difference in MPG.
And given that this rig is often subjected to fairly steep climbs with a boat behind her in 100F+ conditions... and a cooling system noted for its wide operating range... I like the Castrol 20W-50 in there. If it begins to break down... well then it's probably still thicker than 10W-30.
Back to the Onan...
If anything, I like the theory of 10W-30. Should get you the same high temp lube as straight 30, but with better performance at lower than freezing. But yet... according to their chart, the engineers at Onan don't see it that way. Even 10W-40. For my conditions, they recommend 15W-40.
.
FWIW, I'm very familiar with the BITOG site. However, I'm not looking for theory here as much as practical application.
Mex,
Good Lord! I can type 80 WPM, but you must be topping a hundred, easily! Was there an answer in there somewhere?
:)
I think I may have seen it in the "5W-30" comment.
I understand the start up wear concerns, but my motorhome is not a grocery runner. She starts and has to run for hours at a time. Same with the generator. My family are good campers. We don't start the Onan for hair dryers or microwave popcorn. We use her for the A/C and rarely to charge batteries (our rig can go a week on a single charge of the bank and we like peace and quiet in the campground. And thanks to my Mex-inspired, hot-rodded alternator, the bank is charged up again by the time we get home with or without the generator.)
I found it interesting your take on Castrol 20W-50. My father took a 1984, 4-banger 4Runner to 400K with that stuff in it year-round and sold it, still running well, for 2500 bucks. Not sure you can say start-up lubrication was a big problem there. The old hot rodder has also used STP religiously in every rig for most of his life. Oil theory doesn't seem to support that, but he has always and I mean always gotten high miles out of every rig he's ever owned and not one of them was bought new. Hard to argue with that kind of success. Did I mention the 400K mile 4-banger? With only a single timing chain job?
That Castrol is in the pan of the '86 Winnebago with 106K on 'er right now and she uses very little oil. It's the oil I was considering for the Onan, but I'm not sure the little engine that could should be seeing 50W resistance at 212F.
I do like the shorter spread of 20W-50 and 15W-40 which means they should have fewer additives than even 10W-30 and thus prone to less thermal breakdown per given heat situation.
In an effort to garner a little better mileage, I tried some Rotella T 15W-40 in the 454 and she seemed to put more strain on the fan clutch, though I cannot say this anecdote is any way scientific. She did use more oil though, so that became a one-time shot with no discernible difference in MPG.
And given that this rig is often subjected to fairly steep climbs with a boat behind her in 100F+ conditions... and a cooling system noted for its wide operating range... I like the Castrol 20W-50 in there. If it begins to break down... well then it's probably still thicker than 10W-30.
Back to the Onan...
If anything, I like the theory of 10W-30. Should get you the same high temp lube as straight 30, but with better performance at lower than freezing. But yet... according to their chart, the engineers at Onan don't see it that way. Even 10W-40. For my conditions, they recommend 15W-40.
.
