[vrprabhu]

Originally Posted by abhinav.s

If I may, which Motul oil are you using? The 5100? If the manual recommends oil change interval at 2000kms, then I feel you are better off doing that than trying to source an oil to increase the drain interval.

Thanks. I am using Motul 5100 15W50 (Semi-Synth). (Yamaha recommends 20W40)

Originally Posted by a4anurag

I maintained an interval of either 2000 kms and 6 months whichever is earlier.

Thanks. I used to follow the same - this is the first time I have exceeded 2000 kms ( but not 6 months - change the oil once before the onset of monsoon : by June and once in winter by end November; new oil + cold Pune air = sweet sounding engine )

So guess that larger kms (or longer drain interval) does affect the performance.

[sai_ace]

Originally Posted by vrprabhu

Sorry to bump an old thread.

Can you please share the oil change interval which you have been following?

I have been using Motul (Yamaha Gladiator) and find that within 3000 kms the shifting becomes rough (the manual recommends 2000 kms oil change, BTW)

I am surprised, have an RTR and an Apache 150. With synthetic oils the the drain interval is usually 5K+ kms and the max I have pushed is around 7.5K kms on a motul 300v and petronas sprinta. Both the times the mech who changed the oil confirmed that the oil still had life for another 1K kms. And mind you do like to rev my engines hard, the bikes used to see 8k rpms atleast a few times a day.

I make it a point to change the oil when the bike is warm, use a fresh filter and use an oil flush every alternate oil change.

I would suggest before changing your oil to have your clutch cable adjusted to see if your gearshift smoothens . Also have physical examination of the oil and try to study how bad it is.

[mithun]

Originally Posted by abhinav.s

Air cooled engines, in general in vast majority of cases cannot fully exploit the benefits provided by a fully synthetic oil. These are better suited to Liquid cooled engines.

Can you please explain why it's not recommended for air-cooled engines?

[abhinav.s]

Originally Posted by mithun

Can you please explain why it's not recommended for air-cooled engines?

I did not mean to say they are not recommended. I meant to say that the air cooled engines cannot fully extract the benefit of the fully synthetic oils. Air cooled engines wear out the oil faster than their liquid cooled counter parts. Hence the oil change interval recommended by the OEM will be quicker on air cooled bikes.
In case you do want to go for fully synthetic oil, sticking to the OEM recommended grade for all seasons may not work well and you would have to change the grade based on ambient temperatures. The drain interval would be extended by a short duration and not a lot on air cooled motorcycles.
Considering the cost to benefit ratio, it is better to use Semi-Synthetic oils on air cooled motorcycles. But if you can work out the correct grade for the current ambient temperatures, you certainly can use fully synthetic oils as well. My point of comparison for this is limited to the TVS RTR 180 on which I have used both fully synthetic and mineral oil versus the Duke 200 on which it is always been fully synthetic as the service center would not stock or fill up mineral oil at all.

[Crankpin]

Synthetics or Semi-synthetics both are great for air-cooled or liquid cooled small displacement engines. I ran my Duke 200 (liquid cooled) with Shell Advance Semi-synth (10W40) changing it every 4k-5k kms. without any issues and never did the engine run excessively hot...similarly I have been using synthetics in my Activas (10W30) and the oil stays sticky for thousands of kms (approx 6-7k sometimes even more)...it looks burnt but maintains it's viscosity
Idea is to replace the oil at regular intervals. Also, using 10W50 or higher grades actually makes the engine work harder to overcome internal resistance from these thicker oils. A synthetic lighter oil will flow better and flow faster hence your engine actually cools faster...!

Regards

[Sheel]

Originally Posted by ashwinprakas

The Valvoline was the heaviest, the motor was gliding(not grunting) even while almost maxing out the speedometer on the highways.

Originally Posted by Motard_Blr

But I do agree that super high quality oil for a commuter bike run at moderate load and speed, is overkill. The oil ends up being replaced well before it's near the end of its life. So money down the drain.

Replying at a more appropriate thread

Just from the feel and not backing it with up with any evidence, I honestly feel, high grade engine oils don't perform optimally on our commuter bikes. I feel they are designed to perform at certain temperature and rpm's which one can not achieve while commuting. Maybe while canyon riding etc, but still, it would do justice on multi-cylinder high revving, high compression bikes.

[ashwinprakas]

Originally Posted by Sheel

Replying at a more appropriate thread

Indeed would serve to be more useful for a greater audience.

Just from the feel and not backing it with up with any evidence, I honestly feel, high grade engine oils don't perform optimally on our commuter bikes. I feel they are designed to perform at certain temperature and rpm's which one can not achieve while commuting. Maybe while canyon riding etc, but still, it would do justice on multi-cylinder high revving, high compression bikes.

Not exactly. As small displacement motorcycles would be doing higher RPM's at same speeds.

Having frequented interstates on 100cc's and 200+cc's alike, my experience has proven that the 100cc's are at more strain compared to bigger displacement motorcycles the reason simply being;

100 kmph for my Bajaj CT100B happens while bouncing the hard limiter, whereas the same for my Bajaj Pulsar 220 with stock gearing is at half that RPM, with more than 1000 RPM's left to make peak torque and 2000 RPM's to make peak power.

The evidence is visible on oil changes by observing the color, viscosity and metal dust present in the oil.

Some may argue that bigger displacement makes all the difference but factually the only difference between bore size is a matter of mm's unless extra cylinders are involved, in which case the sump size is doubled/tripled to accommodate more oil per cylinder.

The real determinant factors are the RPM range of operation and compression ratio, which is why my previous commuter the Bajaj Discover 100 4G running a slightly higher compression ratio than my Bajaj Pulsar 220, rips oils apart while running interstate, even the infamous Motul 300v which had to be drained at around 1.3~1.4k km's due to oil burning which started before the 1k mark, the only reason we waited to change the oil until we got home was due to us riding at night.