Any advantages to use Rotella T6 or T5 over T4?
 

I've been using Rotella T4 15w-40 a majority of the time that I've had my KPX 250 and am wondering if T5 or T6 would last significantly longer. I've been changing the oil at 1000 to 1200 miles and wondering if I can safely do 1600 to 2000 mile intervals with T5 or T6.

Part of the allure of synthetic is the ability to have it last longer than conventional but with most of the China bikes lacking an oil filter, although we probably could get away with longer intervals, i don't fee comfortable doing more than 1k on the oil i currently use, T4 and would feel the same with T5 or T6.. so my opinion is stick with T4, it should handle 1k and probably way more than that but key being to change every 1000 miles.
The only way to really know how long the T4 could last would be an oil analysis and then compare that to T5 or T6 over the same duration.

I use T6 purely because I have lots of it around, and I use it in my other "real" bikes that have oil filters in them also. But as tknj99 said, it's surely overkill for our dinky Chinese bikes with their short oil change intervals. T4 is also marginally cheaper, so there's that.


I don't think you'll see any performance or longevity benefit with conventional vs. synthetic if you're throwing the oil away within 500-1000 miles anyway.

I always thought that synthetic oil handles heat better.

All my current Hawk has run after the first oil change has been T6. 15w40 T6 to be specific. Paired with my oil cooler I can go an incredibly long time between oil changes, and my bike runs and shifts so smoothly.

How long?

About 2k miles, and I could honestly go further.

Would it be unreasonable to think I could go 1800 to 2000 miles using T6 in my KPX 250?

I don't think it's unreasonable. I suggest running T6 for 1800-2000 miles and then send a sample for a UOA. The results will tell you if you should go longer or shorter.

https://www.blackstone-labs.com/

I am not an oil expert! The following is just what I've learned/read/been advised during 50 years of riding.

Oil change intervals really depend on how the bike is used. Guys or racers who run at high revs all the time should change oil more often than the guy who just rides normally. Those who ride in very cold areas should change more often than those in temperate areas to avoid condensation buildup. Those in very hot areas should change more often because excessive heat breaks down oil faster.

The oil change intervals in the air cooled bikes I've had in the past depended on usage. If I got caught in traffic in hot days I'd change oil more often than 3000 miles. Dirt bikes oil got changed very often. What is "very often"? Depends on how hard the bike was ridden in what length of time. Could be a couple of months and could be a week.

On my liquid cooled 2020 400 KRT Ninja and 2021 Lifan KPR 200 I use any brand 10w40 mineral motorcycle oil and change oil and filter every 3000 miles. The Ninja has 15,000+miles and the KPR now has 10,000+ miles and both are running just fine.

I second everything said here. Change intervals will depend on conditions and how the bike is ridden. I don't go off of a mile interval, but by the feel and smell of the oil. At a bare minimum I will change the oil once a year if I don't manage to ride the bike very much, such as last year where I only put a few hundred miles on it.

The oil cooler made a big difference for my bike and the way I ride in making the oil last a lot longer. I ride my bike about 70% of the time at sustained speeds between 45 and 65mph, which is where the oil cooler does the most good, especially once I start pushing it above 55mph where the motor is working hard. If you do a lot of slow speed riding the oil will still get heat soaked even with a cooler because of a lack of airflow, and this will affect the longevity of the oil.

Just a fun fact related to this topic. CSC states 2500 mile oil change intervals for the TT250. These cheap little engines are also based on the CG125 design, which was designed around the concept of being in environments where they wouldn't get regular maintenance. Basically designed to still survive even when working with dirty crappy oil.

My VFR1200 engine has factory recommended intervals of 7500 miles with standard Honda GN4 oil. I don't go that long with it lol

a quart of prevention is worth a barrel of cure.

Thanks for all of the feedback. I typically ride in the 35 to 45 mph range and usually not much stop and go traffic and have been changing the oil between 900 and 1200 miles. I'll wait and see at what point I start seeing a difference in how the oil looks after 1200 miles this time. Before my last oil change this week, I did a 30 mile ride and immediately drained the oil as recommended by ARiemann1. I immediately noticed how much smoother shifting was than after any other time I've changed the oil.

https://www.youtube.com/watch?v=IxmzCoeLPPE