20w50 for high horsepower application

The 2 strokes are supposed to get a 400 weight oil, not a multi grade. Our experience in 2 cycles with multi grade it increased oil usage. But that's not the question at hand. Yes some,.not all 60's have big bearings. I don't have an issue with 15w40 but if a better oil grade is available for higher horsepower that's what I want.

I understand they are supposed to run a straight 40. Ironically enough, factory recommendations on e one fire apparatus of 500hp 8Vs was 15w40…it’s right on the door placard. None of the units I service burn much, if any.

The S60s I have experience with (mid-late 90s and mid-2000s) all have a very large bearing surface area. I personally would run a 15w40 unless UOA evidence proves the film strength is not enough.
 
On a related note... I was looking at Redline Performance series: the 20W-50 is ACEA A3 rated only (so not PCMO diesel rated) while the others are A3/B4 rated (PCMO diesel and gas rated). I tried asking through the website why that was but never got a reply.

20W50 mineral has little to no benefit over a semi or full synth xW-40 imo... the viscosity index is so much lower that if the oil gets truely hot the HTHS might not be any more than for the lower synthetic grades.
 
Was Pretty common to see high HP boats run this.

The engine load % is beyond what cars see on tracks with significantly longer time periods of full throttle load.

Combine it with brutal drivetrain shocks and a lil bit bigger cushion can help.
 
It might be helpful to know a bit more specifics about the application. Like is this a line haul or vocational tractor or farm tractor; or a toy sled puller or toy souped up farm tractor; is it going to be used in Canada where GCWs can be quite a bit over 80k lb but winter temperatures colder; in mountainous regions; etc. And drivetrain information like transmission, axle ratios, tire size etc.
I have personally seen road trains in Australia with GCW in the 3-400,000 lb range operating in high temperatures. With Series 60 engines. And Doug Hilary has seen the insides of many of those engines, run on Delvac 1 5W40 (CI4+ type), for up to 1.6M km.
Also the emission level if any of the engine (I suspect it’s zeroed out on that).
Even before I see that information, unless the engine is ridiculously turned up, I suspect D1 5W40 will be fine. Even if it’s ESP, though my personal preference is SHC.
 
Even hot-rodded diesels don't run very high engine temps. Diesel combustion is very thermally efficient, transforming the fuel-air mixture into power much more efficiently than gassers, which means very little heat is produced.

I would say the difference between a Xw40 and Xw50 oil will be negligible in terms of gains in performance. Some may even argue that a "thicker" oil can create problems for pressure and flow, but I'm not an expert.

The only reason I'd go thicker is if the engine (and we're likely talking about one with high miles) is burning more oil than typical. But if it was my diesel -- and I've had quite a few over the years, all modded -- I would use the best quality synthetic diesel oil I can find at reasonable prices and that meets the engine spec required. Then I would do several UOA to establish wear metals trend, fuel dilution and TBN, to see where the sweet spot for changing it out is.

I would hope that the EGR has gone missing or is turned off, as that will be the single best thing you can do long-term for your diesel. This means much less soot in the engine and thereby in the engine oil, circulating around like sand in the cracks causing extra wear.
 
The heat in the oil doesn't come from combustion though, but from shearing the oil. And diesels do shear oil much more than NA gas engines at the same rpm, due to the higher torque. and then there's the turbo, that does get HOT and has oil circulating through it.
 
My buddy in Australia mentioned when they turn up their series 60 engines they run a 20w50 oil. But they don't see the temperatures in the Winters like we do. I'm not familiar enough to make this decision, but in cold temps, -10 on up would 20w50 be to thick for my engine in the states?
I'm trying to find out if it's a good idea myself. Just bought a 1998 international 9400 eagle 12.7 60 series with 800k on a rebuild that is running Mystic 20w50 . Wouldn't that be the equivalent of 15w40 with Lucas added?
 
I'm trying to find out if it's a good idea myself. Just bought a 1998 international 9400 eagle 12.7 60 series with 800k on a rebuild that is running Mystic 20w50 . Wouldn't that be the equivalent of 15w40 with Lucas added?
I'd say no and I concur with everything stated above that 20w50 is to thick if your in the states. I've discovered that in my research there isn't a lot of 20w50 heavy duty available in the northern states, but the closer you get to the equator the more popular it gets for obvious reasons.
 
I would say the difference between a Xw40 and Xw50 oil will be negligible in terms of gains in performance. Some may even argue that a "thicker" oil can create problems for pressure and flow, but I'm not an expert.
Not at operating temperature - PD oil pump ensures that. Of course the "W" rating is important for cold start-ups, but that's a different discussion.
 
The heat in the oil doesn't come from combustion though, but from shearing the oil. And diesels do shear oil much more than NA gas engines at the same rpm, due to the higher torque. and then there's the turbo, that does get HOT and has oil circulating through it.
The majority of the heat comes from oil shearing ... but some does come from other sources like the heat in the ring pack, cylinder walls and bottom of the piston dome (which is indirect heat from combustion) if there are oil squirters. So the split of where heat comes from depends somewhat on the engine design.
 
In Oz you probably have access to HDEO 15W-50’s that we don’t see up here.
A full-syn 15W would be fine down to -10C.

Penrite seems to offer a lot of ‘thick’ oils, PCMO and HDEO, see what they have.
 
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