Modern oil in old bike

[pete]

Just a bit of info... we over here in Aus don't get Rotella and the diesel ones we do have don't have as much zinc and some of the other bits and pieces in our diesel oils, so it's not quite the same.

I ran Castrol GTX 10w40 diesel oil for a while and it seemed find but I have switched to Penrite HPR15 15w50 semi synthetic oil and it's a little better for gear changes etc. It's also a little cheaper as a 5L bottle is a similar price to a 4L bottle of the Castrol.

I switched to this after trying some others and chatting to the Katana guys who have had excellent success with it.

[bonanzadave]

I use Mystik 10W40 JT-8 in every engine I own. $52 for a 5 gallon bucket with a $25 rebate. Thats $1.35 a qt.

https://www.mystiklubes.com/do/product/663002002

[Nessism]

Motorcycle or diesel oil is the stuff.

Modern auto oils are less desirable due to reduced zinc and phosphorus levels compared to these other oil formulations. Zinc and phosphorus are critical anti-wear additives, but bad for catalytic converters, thus the reduced levels in auto oils compared to when our GS bikes were made.

[GS1150Pilot]

Rotella T once again this past week for the oil change. Shifts like a dream.

[Grimly]

Has anyone used universal tractor oil - STOU. They claim it's ok for wet brakes

I was about to try that a few years ago - went down the local creamery [1] and had a look to see what the farmers were using, but discovered they were all buying Finol Kappa 15W-40 turbo diesel motor oil, and as it was at the right price (probably why they were buying it) got some for my vans. Later, I used it in the GS, with no problems, as you'd expect. That, and Tetrosyl 15W-40 from the same source.
If I come across some STOU synth at the right spec and price for me, I'd still give it a whirl.

[1] For other readers - the local farmers' supply store is known locally as "The Creamery", relating to a history of rural famers' co-ops which brought in agri-supplies as well as buying in the milk and seperating it, which was their main business. Over time, many of these stores have amalgamated and expanded, so that some of them are now full-on hardware sheds with needles to anchors in stock.

[1_v8_merc]

I run rotella in every bike I own. From the GS, Bandits, and kawasaki 1200 and gpz 1100. I actually convinced my brother to run diesel oil in his sport bikes, as he was having trouble with clutch slippage, running regular car oil!

[limeex2]

Another nice thing about Rotella, If are on a road trip,it is easy to find and top your bike if needed.No need to carry special oil.return any extra to service dept if they have one for disposal.I started running it in my Newer generation Triumphs and it works great. I used Mobil1 or GTX, but found it shifted harder with a little clunking.So now I use it in all my 4-stroke stuff and I dont have 3-4 different brands and weights of oil laying around.