Oil Viscosity after modifications

[MikeCR]

Hey Guys,

I have a 2015 with ramair and an exhaust from @ozrider (and appropriate map, no dyno yet). I was starting to write Les an email when I thought maybe this conversation would be useful for others with similar questions.

I am getting ready for a spring oil change and started to wonder if I should be putting -40 or -50 into this thing.

From what I understand -40 is happy up to 104F/40C which handily covers Iowa summer temps. But obviously the engine is one hell of a lot hotter than that. Which leads me to believe that (10W)-50 is really where I want to be. Even if the radiator is super efficient there is no way the engine temp is not exceeding 104.

With the 10W covering my low end is there any reason not to go -50 for the top end? (assuming the bike is getting hot enough to melt it; which is sort of the real question)

Thanks!

 

[warp9.9]

15W50 was the original oil specifications for the Rocket with a alternative of 10W40. I have never used anything but 15W50 and 20W50 in my bikes. Also not pushing oils but some have noted a better lubricity feeling of the Mobile 1 oils. I use Red Line and Motul comes highly recommended

 

[MikeCR]

Good info thanks!

Just based on the order provided in the manual "10W/40 or 15W/50" I assumed the standard was 10W/40.

My vocabulary started with Castrol and Mobile 1, will definitely look up motul and red line.

 

[Gregger]

Some time ago, I spoke to the former owner of a maw and paw Triumph dealership about oil viscosity for the Rocket. He performed most of the wrenching on the bikes he sold. He did a lot of work on Rockets. He recommended any 10W-40 fully synthetic motorcycle specific oil for colder climates such as we have in Northern Ontario. For the hotter areas, he recommended the 15W-50 or 20W-50.

Chose your poison....

 

[MikeCR]

Thanks Gregger!

I think my primary concern with going up to -50 oil is that its not quite hot enough here (100F is really hot for Iowa in the summer) to melt it. Maybe 15W-50 is a decent compromise. knowing I will ride it down to 40or50F in the fall.

I mean I will almost never ride it below freezing so 20W-50 would even be fine for bottom end. Its really more top end that I'm concerned about meeting.

 

[sonny]

I ride all year. Cold winters and hot summers here in Oklahoma. 10W-40 Mobil from day one. Do change the oil every 5,000 miles. I could see using 20W-50 in a Harley but why would you do that with a water cooled engine? Camshaft ladder after 50,000 miles. Great tattle tale that oil is doing its job. 99 percent of mileage done on open highway at or around 70 miles per hour.

 

[MikeCR]

Good point sonny, indeed this is my first water-cooled bike so I really don't know how much I can trust it to keep temps down.

Also oil viscosity tables confuse me somewhat. I get its ambient based but really I want to know when -40 or -50 is most effective in terms of engine temp. That way the air vs water cooling would be taken out of the equation and I could just pick whatever can handle the actual engine temps.

(And also why i tagged ozrider early on, I don't know what to expect given my current setup vs stock for example)

 

[sonny]

Am a firm believer in if it works don't Buck with it. I can understand using a heavier oil in a super built bike. With just Ramair, 3 into one exhaust and a set of street cams I'll run the 10W-40. This way i know it is getting the proper lubrication from start up to open highway.

 

[Bernard Vinet]

In Montreal where the weather barely get over 38c I'm run 20-50 Amsoil. Here there is not such thing as a short ride . Average 300+ Km on short ride. So I want an oil that can take long highway & plenty of congestion on the way home. Which is where bike tends to heat up the most . If idling exhausts pipe glows red hot.

 

[warp9.9]

Good info thanks!

Just based on the order provided in the manual "10W/40 or 15W/50" I assumed the standard was 10W/40.

My vocabulary started with Castrol and Mobile 1, will definitely look up motul and red line.

I use the redline based on two things. It is one of the two oils megacycle cams told me they like (the other being Motul 300V) and its seams so far to be readily available since its made in the USA. Otherwise I'd be running the Motul. I go look at the wording on the weight but from what you said I'm thinking the just swapped the weights around once Mobile 1 kicked them to the curb. My point to you really no matter which weight you choose. I've noticed guys who have changed to mobile 1 have talked about noticable differences in shifting.