About time for my 2nd (1000 mile) oil change and I am jumping to full synthetic 10W40 Castrol Syntech. I had heard great stuff on Mobil 1 redcap, but this is gone, replaced (I believe) with a gold cap. I am not sure if it's the same formula, so I'm going with the Castrol, which I've also heard good stuff about.
Maybe I'm over cautious...will most any auto type 10W40 work as long as it's not "energy conserving" in the SAE sticker? This Castrol is API Service SM SL SJ CF which I understand exceeds SF/SG.
What might I expect in any changes in how my 03 Savage runs? Some say it smooths shifting (mine is "clunky" at times).
...or better yet, any reason that I shouldn't put this stuff in the machine? (other than the 4 something a quart cost...)
Thanks for inputs...don't want to get an "oil war" going here...
Dave
03 Savage, 918 miles

My wife's 96 800 Intruder loves Castrol Syntec blend 10W40. But not straight syn. My 98 Savage works best on 20W50 Castrol GTX dino-juice. It didn't like synthetic 10W40. Changed the oil, rode to a rally 3 or 4 hours from home. Next day did the rally "circuit", about 30 minutes of crawling at idle speed. Bike started sonding funny, so I checked the oil. It was ALL gone. Replaced it with GTX 20W50, hasn't been a problem since.

Best advice is to try it and see how your bike likes it. Manufacturing tolerances aren't very consistent, some parts could be high end of the scale, other low end of the scale, on the same bike. Just how mass production is. Find an oil your bike likes.
-WD

Reelthing and WD are you guys talking about Cycle oil only or auto oil? just want to make sure. cycle oil around here is far more exp. than auto oil. 8)

Well, took the bike for a short spin to warm it some then swapped out oil and filter, fresh syn in there now...and it started drizzling as I was finishing...rats!
Forecasting rain and snowshowers tonite, occasional  rain tomorrow. I am really, really ready for some good weather right about now!
I did get the engine run some, parked, after the change. Two quarts even, shows on the high end of the range in the window.
Piece of cake with my 2 wrenches, drain pan, funnel, and a rag. Not too bad for this rookie wrencher.

Dave

Thank you sir 8)

Motorcycle (and ATV) oils have additives that help them survive the demands of the clutch - preventing premature breakdown.  I'd never use a car oil in any cylce or ATV with a clutch.  Car oil might seem alright, but I doubt long term it would show itself to prevent wear like a motorcycle oil.  I use Honda GN4 in every bike/ATV I own, they make a synthetic, too, but I'm sure the others mentioned are good, too.  Use motorcycle oil, you GET WHAT YOU PAY FOR, it's not some conspiracy

Z400
CRF230F
S40

My 98 is 7+ years in my possession. I have used the factory 10W40 twice, once one I took delivery of the bike and then after dealer service (bike wasn't happy). I tried factory 20W50 (bike was VERY unhappy). Quaker State 4X4 full synthetic (supposedly for low RPM, low speed operation) and that was a BIG mistake (the oil disappeared in less than 24 hours of riding). I switched to Castrol GTX (North American market) 20W50 CAR dino-juice. The bike never ran or shifted better. Suzuki quality control is rather laughable, so you have to try different weights and types until you find what works best in YOUR bike. No two Savages have the same operating characteristics. They are close, but they aren't the same.

When I rode HD and old (pre-unit) British vertical twins, I used Cessna (yes, the airplane company) 50 weight winter, 70 weight summer for the engines, 90 weight gear oil in transmissions and primary cases. Tried the HD motorcycle oil once, it cost me a very sweet Knucklehead engine. Rebuilt it and switched back to Cessna oil. Which at the time was dino-juice.

Formulation is less important than frequency of changing the oil. My Savage was quite happy on once a year GTX and new filter change. This year, if I can start riding again, it will get 3 or 4 oil changes. GTX and new filter each time.
-WD

Lancer do you get your Amsoil from Walyworld?

What is everyone else running I put in the suzuki stock stuff because a case of it came with the bike but I have noticed the gears are not quite right and the clutch is not consistant in its feel. seems to give a little when the bike gets warm.