Friction Modifiers as mentioned in the 1985 GS450GA owners manual

[CallMeHoovy]

Hello everyone!

My first post here so go easy on me. When browsing my owners manual looking for oil recommendations for this bike it appears that friction modifiers are actually intended to be used in this bike. I'm guessing this has to do with the suzukimatic transmission. Is this a typo or am I good to go put standard car oil in this bike. TO CLARIFY it has motorcycle oil in it now as I was not sure but if I can save money on my next oil change please by all means let me know.

[Suzukian]

Try this link.

https://www.amazon.com/1985-Suzuki-GS450GA-Synthetic-Change/dp/B00BMWEXG2

[eil]

The only reason we have to use special oil without friction modifiers in most motorcycles is because of the wet clutch. Since your bike doesn't have a wet clutch I would therefore venture to guess that you can run any 10W-40 that your heart desires.

[Suzukian]

His bike is an automatic. That's why Suzuki has them use a particular oil. It has to be a full synthetic. I would highly recommend getting an synthetic oil recommended for your bike, or you could end up with problems with the torque converter. The bike calls for Synthetic Oil, before Synthetic Oil was a "thing". Don't put regular oil in that bike. Research it for yourself. Then you will know for yourself.

[Brendan W]

When that was written SF was the bells and whistles, top dog oil.
All multigrade oils have friction modifiers, that's how they get from 10 to 40.
Friction modifier means different things in different contexts.
Modern car oils can cause trouble with wet clutches.
Any SF or later oil should be fine provided it does not have eco anywhere on the label.
Eco would denote a class of friction modifier to improve fuel consumption at the expense of wet clutch performance.
A lot of us move to 15W40. A 15 almost guarantees there will be no bad friction modifiers

[Suzukian]

Those bikes require Synthetic oil, mostly because of the torque converter. I worked in a Suzuki dealership when those bikes were sold. The few people who purchased them just purchased the Suzuki Oil for that bike.

It's still made.

https://www.amazon.com/1985-Suzuki-GS450GA-Oil-Change/dp/B00BL4XRQI

[rphillips]

GS450GA manual says use an oil which is rated SE or SF and 10 W 40 wt.. as long as those specs are met I don't see if motorcycle oil, car oil, diesel oil makes a difference. If it did I think they'd have told us so, they're pretty good about giving us warnings.... Seemed odd, Looking up these specs., says SE is suitable for vehicles mfg. in North America from 1972 thru 1979 and SF is suitable for vehicles mfg. in North America from 1980 to 1988, I saw no mention of synthetic.

[bitzz]

Oh good ... an oil thread.
SAE SF oil in 1984 wasn't synthetic. (SAE stands for Society of Automotive Engineers. That's a hint). If a 1984 Suzuki GS450 NEEDED synthetic oil, the manual would have stipulated synthetic oil. It did not. Synthetic oil is not new, the Nazis used lots of synth oil in their fighter planes in WW2.
ALL motor oil has "friction modifiers". ALL.
Motor oil rated SAE SG/SH is the last "car" oil that can be used with a wet clutch, like a motorcycle or a VW bug. Anything newer will not pass a JASO T903 test, so won't get a MA rating. The newer MA2 standard is for motors with catalytic converters. Passing a T903 test DOES NOT mean the oil is recommended for a motorcycle, but ALL motorcycle oil must pass a T903 test. They didn't have the JASO T903 test in 1984.
The JASO T903 test is one test out of hundreds that goes into rating motorcycle oil... so having a MA/MA2 rating, in itself, DOES NOT mean the oil is recommended for a motorcycle.
To change Regular 30 oil (what comes out of the ground) to 10 weight or 50 weight, you would use VISCOSITY modifiers... so all motor oil except REG 30 has viscosity modifiers. Reg 30, like ALL motor oils, has viscosity stabilizers.
1984 ATF had a viscosity of around 7-9, which is not viscous enough for a crankshaft bearing
The internet knows *@%^$*@%^$*@%^$*@%^$ about oil. A good part of what's written here is just plain wrong, just like every internet oil thread. Use what the manufacturer recommends, NOTHING ELSE. Diesel oil works great in low revving diesel motors, I wouldn't put it in a high revving motor. High revving motors need anti foam, LOTS of anti foam... and if it doesn't have lots of anti foam, like diesel oil,you're pumping compressible air into the crankshaft bearings. Air is a lousy lubricant.
I don't know if SF oil is still available, but SG oil is. Any auto parts store will stock it or can get it. Pre catalytic cars want SG oil. Oil after SAE SG has teflon in it. Teflon soaks into clutch plates

[rphillips]

Very interesting, thanks. Seems you've been around this stuff before. If his manual says use SE or SF and 10 W 40, what should he look for on a can of oil at O'Rileys to be sure he's good to go.

[CallMeHoovy]

Oh good ... an oil thread.
SAE SF oil in 1984 wasn't synthetic. (SAE stands for Society of Automotive Engineers. That's a hint). If a 1984 Suzuki GS450 NEEDED synthetic oil, the manual would have stipulated synthetic oil. It did not. Synthetic oil is not new, the Nazis used lots of synth oil in their fighter planes in WW2.
ALL motor oil has "friction modifiers". ALL.
Motor oil rated SAE SG/SH is the last "car" oil that can be used with a wet clutch, like a motorcycle or a VW bug. Anything newer will not pass a JASO T903 test, so won't get a MA rating. The newer MA2 standard is for motors with catalytic converters. Passing a T903 test DOES NOT mean the oil is recommended for a motorcycle, but ALL motorcycle oil must pass a T903 test. They didn't have the JASO T903 test in 1984.
The JASO T903 test is one test out of hundreds that goes into rating motorcycle oil... so having a MA/MA2 rating, in itself, DOES NOT mean the oil is recommended for a motorcycle.
To change Regular 30 oil (what comes out of the ground) to 10 weight or 50 weight, you would use VISCOSITY modifiers... so all motor oil except REG 30 has viscosity modifiers. Reg 30, like ALL motor oils, has viscosity stabilizers.
1984 ATF had a viscosity of around 7-9, which is not viscous enough for a crankshaft bearing
The internet knows *@%^$*@%^$*@%^$*@%^$ about oil. A good part of what's written here is just plain wrong, just like every internet oil thread. Use what the manufacturer recommends, NOTHING ELSE. Diesel oil works great in low revving diesel motors, I wouldn't put it in a high revving motor. High revving motors need anti foam, LOTS of anti foam... and if it doesn't have lots of anti foam, like diesel oil,you're pumping compressible air into the crankshaft bearings. Air is a lousy lubricant.
I don't know if SF oil is still available, but SG oil is. Any auto parts store will stock it or can get it. Pre catalytic cars want SG oil. Oil after SAE SG has teflon in it. Teflon soaks into clutch plates

Thanks a ton for the large response. So SG it is to avoid any possible issues. Would Synthetic still pose a benefit over conventional for the health of the engine and torque converter?

[Brendan W]

Thanks a ton for the large response. So SG it is to avoid any possible issues. Would Synthetic still pose a benefit over conventional for the health of the engine and torque converter?

Synthetics are supposed to be more stable, slower to degrade. In that sense, yes, there is a benefit.
However if you will be changing after a few thousand miles anyway, you would be right in asking if you will ever see any of that benefit.
Cars running full synthetics now have 18000 mile change intervals.
When I drove a lot more I used full syn but chickened out at 12000.
Now my annual car mileage is half that and I will use semi syn, or syn and change annually.
For bikes, nothing I ever owned was built after 1996 and none ever specified full syn and I change at 3000 or annual whichever comes first.
Given the hammering that gearboxes give oils, I don't believe that even a fully syn oil should be left in there for more than 3000 miles.

[rphillips]

Always wondered why, 20 yrs ago the oil changes were every 7500 mi., or 5000 mi. under extreme conditions, today with better oils and engines it had dropped to every 3000 mi., that's more than twice as often, When I first heard of the 3000 mi. it was from a Quaker State ad. within a few yrs. after that the new owners manuals were changed to 3000... very suspicious.

[Suzukian]

I was told when I purchased my Subaru Forester I had to run it on synthetic oil. If I drove it normally, I could change the oil every 6000K miles. Just maintain the oil level.

As long as the oil for my ZZR11200/GS750ES has the API SE, SF or SG or API SH or SJ with JASO MA, Viscosity SAE 10W40, you're good to go. I am running full synthetic in the ZZR1200 as it only has 3500 original miles on it. I run Valvoline 20w50 in the Summer months on my '83 gS750ES, as it has been getting very hot up here in the North East.

[bitzz]

Always wondered why, 20 yrs ago the oil changes were every 7500 mi., or 5000 mi. under extreme conditions, today with better oils and engines it had dropped to every 3000 mi., that's more than twice as often, When I first heard of the 3000 mi. it was from a Quaker State ad. within a few yrs. after that the new owners manuals were changed to 3000... very suspicious.

My 1970 Norton wants an oil change at 1200 miles, same for the 1972 Triumph, the 1973 Ducati is 1000 miles, 1974 Cb500T 1500 miles, 1979 GS1000 2000 miles All according to factory service manuals

High lift cams, high seat pressure with shims and buckets KILL viscosity modifiers. Older oil had a lot less viscosity modifiers. To make oil that is 10w at room temps and 40w at operating temperature requires a lot of polymer magic. Some of the polymer viscosity modifiers look like a little spring. At room temp they are coiled tightly and short, apply heat and they stretch out, raising viscosity, and when you jam them under a cam follower the "spring" breaks and BINGO... less viscosity. (Did that make sense to you?)
Older motors don't rev as high and have a LOT less valve seat pressure.
In cars, but not bikes, the oil requirements changed greatly in the last 30 years. 30 years ago 0.003-0.0045" main/crank bearing gap was the norm, now some are running less than 0.001" (the motors that use 0w/xx oil). We need special/magic oil for cleaner emissions

Something to contemplate: New oil contains a bunch of magic, older spec oil doesn't. The volume in your quart of SG oil that isn't magic has to be filled with something... SG oil has more lubricating stock than SM. Lubricating stock is what is slippery and what you thought you were buying oil for.
Use the oil that the engineers that designed your motor designed your motor to use. It is a lot more than slippery in a bottle.

[Grimly]

I'll just stick to synthetics.