88 CI Air cooled V-twin vs 500 CI+/- water cooled industrial diesel? Worlds apart with different lubrication requirements.

The recommended oil for my Kubota diesel is a SAE 30/10W-30. Why? The tolerances are so tight, that the thinner oil is needed to reach all the necessary spaces. No, I don't use Kubota oil. I use Mobil-1 in the specified weight for that application.

Used to use Rotella-T in my F-250 until I switched over to synthetic. I'll use Mobil-1 or Rotella synthetic whichever is cheaper at Wal-Mart at that time.

 

If you check your owners manual , you'll find the temp range that allows for use of a 10/40 wt oil. Above 40 they say to use 20/50. Also it says if Harley oil isn't available to use a diesel oil. Diesel oil has about everything an aircooled motor needs to run perfectly. I don't know if you could find a 20/50 diesel oil but if you can, use it if the temps are right.

 

It's great for trucks. Is your Harley a truck? Is it a Diesel?

It always amazes me how people can spend 20 thou on a bike, hundreds of dollars on chrome bling,...... then skimp $3 on oil, one of the most important things to insure a long motor life. Truly pathetic,.....

 

Almost everyone in the air cooled VW forum uses that oil. Both motors are reasonably close design. The rotella oil has alot of zink in it Which was good for something Bearings? I was told at the local harley dealer that i could, In a pinch, add that kind of oil when i was on the road and it was all i could get. (preferred over reg. car oils ) Now for my disclaimer I'm not saying i would use this oil. lol

 

There is an oil forum here, and after reading much of the geeky stuff, there are minor differences in every oil type and weight due to the additives spec'd by the oil manufacturer. I have been a faithful user of Castrol oils in all my junk for Thirty-five years, and will most likely continue by using their RS V-Twin 4T SAE 20W50 Syn-blend in my newest scooter. Their RS GPS 4T is also a blend, rated for scooters, but for the lack of their V-Twin rating is four dollars cheaper a quart. I have not been able to scope out the difference in them save for the price. Have to go get geekified again if I wanna get to the bottom of that one. Still recovering from my last trip there. Lol One probably just a fraction of 1% of a given compound additive different. There are only four or five main ones they chose to work with.
If I weren't as faithful a user of "Castrol" oils, which got hammered on in the forum for lack of something. "Those Krafty Germans might know more than they let on" I personally would most definatly consider the use of the Rotella T. And for the price, it's still a consideration because it has all the stuff in it to help avoid high temp shearing and breakdown. The only possible lacking element might be one it already has, just in a smaller concentration. So being that each and every manufacturer has such a varying degree of components in their additives who knows which is truely right for our motors.
My Two bits worth!

Bob

 

I use it and have never had an oil issue in 75,000 miles. I send in samples to blackstone labs and here is the thing about rotella 15-40 it has a higher flash point and it stays in grade. I have also used mobil 1 20-50 v-twin and after 4000 miles there is very little difference between the two. You have to remember as much as we love our harleys the engine is actually a cheap unsophisticated motor that could probably run on melted butter.

 

mtclassic. . .I agree with you that there is little difference between the Rotella and the Mobil 1--both solid performers with good wear numbers, but there are differences though. The additive pack for the motorcycle oil is different, probably with a little more zinc, which is a high-pressure anti-scuff additive that's important during cold starts and severe oil oxidation.

I believe in using oil designed for for specific purposes--not everybody does and that's OK. . their bikes, they can do what they want. I fly for a living. . .air-cooled Lycomings. In many respects they're not that different than our beloved Harleys--push-rod actuated valves, large displacement, 2600 RPM redline, and fairly loose tolerances. 20W-50 is spec'd for these engines just like our Harleys. . .for year round use. Compared to motorcycle oil, this aircraft oil doesn't have that many additives in it and it's a semi-synthetic--why? Mobil 1 made a full-syn aircraft oil several years ago and it failed miserably and resulted in some deaths. To simplify, the full-synthetic failed to hold engine contaminants in suspension and they sludged up, resulting in some spectacular failures. Mobil settled out of court in several cases and bought more than a few new engines.

Why is this relevant you may ask? Because as similar as aircraft engines are to our Harleys in many respects, an oil that works great in the Harley (full syn) could destroy an aircraft engine in short order. An aircraft oil in a Harley might work, but the lack of a strong additive package would likely result in excess wear to cam lobes etc. and probably a reduced engine lifespan.

Like others have pointed out, compared to the overall cost of our bikes oil is cheap. You don't have to spend a lot of money to get motorcycle oil--dino oil is fine as long as it is changed according to the manual, and it won't break the bank either--You should be able to find conventional "motorcycle" oils at any Autozone for under $4 /qt.

 

It's not only "still a motor", this motor is aircooled (which translates to getting hot sometimes). It would self destruct on your "melted butter".

How many oil changes, using cheap crap in your oil tank to save $3, would it take to save up for a $200 piece of chrome that does nothing functional for your bike? You think nothing of buying the expensive bling.

Why cheap-out on the lifeblood of your motor? Why do you hate your motor so much?
Does it not give you endless hours of pleasure? "Cheap unsofisticated motor? How rude! LOL
Man, I hope my bike didn't hear you say that.

Fess up,.... are you a poser?


Try breaking the pill in half next time, try a lighter dose.

 

yes I am a poser. I only average over 20,000 miles a year and my bike has no chrome. I have 75,000 on my 04 flhtc that I bought new. I ride for work so even tho I have, no live to ride ride to live chrome it would be fitting. I first started riding in 1971 (born in 59). I have used blackstone labs and vtwin 20-50 mobil 1 and rotella 15-40 had nearly identical zinc and phosphorus counts the rotella has less moly than the mobil1, calcium is about the same too. not much more I can say. Not cheaping out but just using what works. Prior to my Harley I put mega miles on bmw oil heads which are air cooled and always used rotella with no ill effects. Highest early mileage was almost 40,000 in 1999. So I guess you could say I am poser.

 

They have lowered there zinc ratings for the new SM rating. Which is not good in older engines that have flat tappet cams.
If you do run it make sure u add ZDDP or a blue bottle of STP which has the zinc in it.
Any of you who are wondering what zinc is and why the hell would I want it in my oil: it is a sacrificial metal that prevents metal to metal contact. It embeds itself into the pores of metals and basically sacrifices itself to save the metal parts that touch.
They lowered the zinc level because almost all newer engines have roller everything now, and with the dual and four catalytic exhaust systems on newer cars. The zinc found in oil will clog catalytic converters.

I run Amsoil and there v-twin formula has a added dose of zinc. They also have a high zinc formula with anyone with an older car that still has flat tappet cam(s).

DIESEL oil has a low Zinc rating to so just because you use it doen't mean you get any added protection.