Okay, I'm trying to get all the noob questions out of my system for now. 

The synthetic motorcycle store 10W40 is expensive stuff.  I hear that some car brand synthetic 10W40 is just as good, but some have a detergent that could be bad for a motorcycle engine.  Isn't the Mobil1 synthetic detergent free?

Also, since the GS500E has a tendancy to burn oil, do you even need to use synthetic?

Ummm.....no synthetic is not neccesary   Nor is actual 'motorcycle oil'.  I use 10w40 Castrol GTX  ( $2-$3 a quart )  As far as regular synthetic, the only thing I've heard is that putting it into a brand new high-power, wet clutch, engine can make it slip.     Doesn't really apply to the old GS.  But yeah  plain ole  Castrol GTX works great

More than you will ever care to know:

http://motorcycleinfo.calsci.com/Consumables.html#Oil

Just make sure you use oil without the energy conserving label on it, that is what can cause the cluctch slippage.  (Even though I have used it in the GS before  ).

Edit: In my current bike (inline 4 600cc) I have used Rotella T synthetic without issue (6000+ miles), actually I think it has smoothed out the shifting.  I get it at Walmart for $14.00 a gallon.

uh oh. Oil debates are a matter of religion for a lot of people. My personal favorite is the Shell Rotella T diesel oils. They have both a synthetic and a dino oil. Quite cheap at Walmart and the characteristics of diesel oil are pretty similar to motorcycle oil. I like 'em, but I don't try and convert anyone. I'd just stay away from anything that has Energy Conserving on it. Those typically aren't recommended for wet clutches.

Ha, looks like Destro beat me while I was typing.

Like spcterry, I use Castrol GTX in my GS. I've used Castrol in every bike I've had since I started riding in '65. Castrol also goes in my '70 914 since I've had it (1975). I've never had any oil-related problems with either bike or car. I personally think synthetic oil in the GS is overkill. Just use a quality motor oil and change it frequently.

Yup, this debate is age old and will be around forever.

I use Shell Rotella T dino oil.  I change it about twice a year which ends up being every 2,000 miles.  Its not really necessary...but I do it anyways.

-Turd.

I use Accel oil from walmart. $1.25 a qt for 10W40 and its SF rated. Good stuff, just dont put it in your new car.
Cool.
Srinath.

I use motor oil...  The vegetable oil just wasn't doing the job.

Quote from: RVertigo on April 10, 2007, 12:15:56 PM
I use motor oil...  The vegetable oil just wasn't doing the job.

try olive oil, it's a bit thicker under heavy loads

Extra Virgin or the cheap stuff?

Peanut oil...makes everything taste better! 

The cheapest 10W40 Wal-Mart has to offer.  Works fine.

I use the 15W-40 heavy duty truck oils, hard to beat for an air cooled bike.  Mobil Delvac 1300 or Shell Rotella T dino juice, about $8 per gallon.

I use Rendered out Hog Lard and Whale Blubber.Takes a while to Get it Liquified when Cold but makes Everything Slicker than $h!t when it warms up.Makes Wheelies a Whole lot Easier than with Straight 16W25 Squid Oil.

Really the Cheap stuff is all you need.Go to the Dollar Store and Pick up some Pennzoil or STP for $1.75 Quart.

C8

Rotella T Synthetic is 5W-40, the Rotella T Multigrade 15W-40 is dino juice.