Rotella T4,T5, or T6?

[Rich82GS750TZ]

The Rotella threads are making my head spin. The wife is going to Sam’s club tomorrow. I would join her but I’m headed to a motorcycle swap meet in Harrisburg that is in the opposite direction. Anyway, I noticed last time at Sam’s, they have Rotella, and I’ve been wanting to switch. According to their website, they have:
T4 - 15W-40
T5 - 15W-40
T6 - 5W-40

I’m not sure what to tell her to get.

My apologies for starting another oil thread. Just really confused.

[Cipher]

I've used the t4 and t6
T6 seemed to burn off I was often topping up
T4 is fine and cheaper.

[steve murdoch]

Been using T6 for five years in the CBX.

[Nessism]

All good. T6 affords extended change intervals and since the cold viscosity is lower it flows better for cold starts. T4 is perfectly adequate for most people that don't ride in the winter though.

[Rich82GS750TZ]

Ed, I do try to ride through the winter when a nice sunny day happens and it’s over 40deg. F or so. In that case I should definitely use the T6?

[Nessism]

Ed, I do try to ride through the winter when a nice sunny day happens and it’s over 40deg. F or so. In that case I should definitely use the T6?

T4 (15W-40) is fine at 40F. The manual has an oil chart and Suzuki shows 20W-50 with a lower temp range of 14F.

[bitzz]

T4 is OK if you have a roller bottom end
If you don't have a roller bottom end, buy motorcycle oil.

Rotella is NOT good oil, Rotella is CHEAP oil... and the reason you wanted Rotella was higher levels of ZDDP or Zinc dialkyldithiophosphates, and Rotella was reformulated a couple of years ago and it doesn't have high ZDDP anymore.

[Cipher]

T4 is OK if you have a roller bottom end
If you don't have a roller bottom end, buy motorcycle oil.

Rotella is NOT good oil, Rotella is CHEAP oil... and the reason you wanted Rotella was higher levels of ZDDP or Zinc dialkyldithiophosphates, and Rotella was reformulated a couple of years ago and it doesn't have high ZDDP anymore.

One wonders how all those plain bearing cranks survived.
Rotella t4 is just fine.
OIL THREAD!!!!!!!

[Rich82GS750TZ]

Head spinning again. Who knows if a 80 750E or 82 750T has a plain or roller bearing crank?

[Cipher]

Head spinning again. Who knows if a 80 750E or 82 750T has a plain or roller bearing crank?

Plain both and t4 is fine

[Nessism]

Agree, T4 is fine. Motorcycle oil is a money grab.

[Rich82GS750TZ]

Thanks all. Sam’s was out of stock. Have to run errands tomorrow, pick up a new oil filter at the Suziki dealer. Will find T4 at Walmart probably.

[Cipher]

Agree, T4 is fine. Motorcycle oil is a money grab.

I use the OEM specced oil in my kbike and t4 or a comparable spec diesel oil in my old bike.
The old bike is plain bearing but it has something on the order of 60 psi in the oil system. Dont lug and change at proper intervals and any old GS will likely outlive its current rider. It may outlive the age of petroleum powered transport.

BMW is an evil money machine the OEM spec oil is a castrol product. They later ended the association with Castrol and started hawking a slightly upgraded spec under an in house label. Its the same engine same tolerances etc but they trick rich stupid people into throwing money away. Oddly I can occasionally score the Castrol product at walmart for 12 or so bucks a litre. Walmart may reduce to clear but I doubt they ever sell at a loss. BMW advantec is currently 21.99 on amazon.ca but I would be leery of buying it as the price is so high at the dealer people might be counterfeiting it.

Joe Minton had a nice article years ago on plain bearing and how they work and fail. Clean oil and no lugging and your crank journals are floated in oil and the babbit does not get scored.

[Nessism]

I use the OEM specced oil in my kbike and t4 or a comparable spec diesel oil in my old bike.
The old bike is plain bearing but it has something on the order of 60 psi in the oil system. Dont lug and change at proper intervals and any old GS will likely outlive its current rider. It may outlive the age of petroleum powered transport.

BMW is an evil money machine the OEM spec oil is a castrol product. They later ended the association with Castrol and started hawking a slightly upgraded spec under an in house label. Its the same engine same tolerances etc but they trick rich stupid people into throwing money away. Oddly I can occasionally score the Castrol product at walmart for 12 or so bucks a litre. Walmart may reduce to clear but I doubt they ever sell at a loss. BMW advantec is currently 21.99 on amazon.ca but I would be leery of buying it as the price is so high at the dealer people might be counterfeiting it.

Joe Minton had a nice article years ago on plain bearing and how they work and fail. Clean oil and no lugging and your crank journals are floated in oil and the babbit does not get scored.

99.9% of all engines use plain journal bearings.

Regarding roller bearing cranks, some people claim that the rollers can skid instead of roll in some situations if the wrong oil is used. Pretty sure "wrong oil" doesn't included Rotella though. In fact, I'm not sure what oil is "wrong." Maybe those with friction modifiers like EC car oils? The same oils that damage wet clutches, which Rotella doesn't.

[dorkburger]

I’ve used many types of oil in my GSs over the years. At first it was whatever Mobil oil my father had in the barrel in the garage for his construction equipment. Next was ridiculously overpriced moto specific synthetic. I then used the Rotella synthetic for quite some time. Last go, I used the non synthetic to save a few bucks. Both the world and the 1150 are still spinning.