Maybe we should bring up the subject of synthetic oil. A friend runs the additive department of Sunoco Oil Company. They regularly purchase autos from all manufactures, tear them down, take measurements and systematically re inspect until they reach 100,000 miles. They need to do this to make sure there fuels / additives are formulated to work well with the ever changing engine requirements. He stated that autos running on synthetic oils have virtually no wear.

As I understand Synthetic oil actually adheres to metal to protect it unlike standard oils that simply wash between parts. There is a break in period needed with standard oils to seat parts. What that period is…. who knows.

The thing that bothers me about the claim of synthetic oils causing no where is this is impossible. Because of the nature of a 4-stroke engine, oil does not reach everywhere it should. If it did we would be burning oil as well.

The top of the cylinder above the top ring never sees oil if the pistons rings are working correctly. You're going to get wear there, plus the heat of combustion will create a taper to the cylinder over time, as the upper area gets less oil and more heat then the lower.

The valve faces never get oiled... ever (unless your piston rings fail) and this is the part that wears in to create the need to adjust your valves. Every time the valve slams into the valve seat both experience a tiny amount of wear. After several trillion impacts the poor things have pounded each other down and need to be re-shimed to account for the damage done. This is part of the reason leaded gasolines were used earlier on. The lead would melt and bind to the valve/valve seat surface and slow the wear down process. Modern gasolines have "lead replacements."

As for oil preventing wear... I can believe that in the crankcase, especially around the crankshaft. But here's the thing, you're going to get some wear at startup no matter what. And so long as you change your dino oil regularly it should do the same thing.

Our crankshafts are plain bearing crankshafts, which means that they have no round bearings per se... it is just a small curved piece of metal that fits around the crankshaft mounts with about 1 to 2 thousands of an inch of clearance. When the engine stops the crankshaft settles and rests on this, but when the engine starts up the oil pressure creates what is called a hydrolic wedge and the uncompressable oil literally causes the crankshaft to float. So long as you have sufficient oil, and your oil pump is working the crankshaft should never come into contact with the mountpoints while the engine is running. Once the oil starts to break down it will lose some of its ability to protect... and this means wear will start to occur.

Near as I can tell the main advantage of synthetic is a longer duration between oil changes.

Keep in mind I've not tested and torn apart engines after 1 million miles. But I'm also not trying to sell you more expensive oil.

Nice to see you found this site Sev.
Good to have you aboard.

Maybe we should bring up the subject of synthetic oil.
Now why would you go and do that... :wtf :lol:

Just remember... there are a $hit ton of cars around that have 100's of thousands of miles on them on Dino oil. Synthetic hasnt been around long enough to prove itself that mush better.

Basically.. either way, as long as you choose the correct viscosity motorcycle oil and change it regularly, your bike will run great.

Just remember... there are a $hit ton of cars around that have 100's of thousands of miles on them on Dino oil.

For what it's worth, car motors are extremely easy on the oil in their crankcase. Most bikes, on the other hand, use that same oil in the transmission, where oil is ripped apart fairly quickly.

I have a few kinds of oil analysis reports from a couple of different bikes and my car, done by Blackstone Labs. (http://blackstone-labs.com/) I'll post up a Big Post later after dinner and whatnot.

So here we go. As I stated earlier, I get my oil samples analyzed by Blackstone Labs. They run tests on it to give a breakdown of oil additives, including anti-wear agents, as well as fuel in the oil, water in the oil and antifreeze in the oil. It's a pretty good indication of how your motor is doing and how well your oil is holding up.

I started with 2,500 miles (5,000 mi on the bike) on some Mobil 1 10W-30 car oil. That sample suffered from a reduction in viscosity and flashpoint, due to trace amounts of fuel in the oil. The viscosity was out of spec enough for the oil to have lost a good deal of its protective qualities. So 2,500 miles of mixed city and mostly freeway/highway riding is about the limit for Mobil 1.

Next up was another 2,500 miles (7.5k on bike). Since the weather was warmer, I switched to Honda GN4 20W-50 oil. There was a significant amount of oil in this sample compared to my other samples, but Blackstone Labs states it's typical for a motorcycle engine. Due to 1% of the sample being fuel, the viscosity and flashpoints were well under spec. The oil was most decidedly done at that mileage. It should last longer if there's less city riding done, but my bike is my commuter so it sees a lot of really short trips.

The latest report is 2,750 miles (10.1k on bike) on Castrol GTX 10W-40 car oil. This is the fresh stuff I poured in my bike before my five state Spring Break trip (http://www.honda599.com/phpBB2/viewtopic.php?t=751). There was only a tiny trace of fuel in the sample this time, but the viscosity test showed, once again, the oil was out of spec again. The flashpoint was just barely under spec (spec of 375 F, tested was 370 F). The lowered viscosity made the oil test like a 5W-30. Also noted on this report: my pistons were still breaking in at 7,500 miles, but had stopped at 10k miles, judging by the amount of aluminum in the sample. Also, Castrol GTX has the least amount of anti-wear additives of the oils tested. It had significantly less moly than all other oils I've tested as well as less calcium and magnesium, which are both detergents.


So what do these three reports tell us? Well, from what I gather is my Hornet chews up oil in under 3,000 miles. At that mileage, the oil has lost a significant ability to lubricate my motor. For what it's worth, my Honda Civic's Castrol GTX 5W-30 comes out in much better condition after 5,000 miles of use.

I'll end with the one lesson I wish to impart on everyone: it doesn't matter much what kind of oil is in your bike as long as it gets changed often.

(edit: if you'd like to see one of the reports, check it out. (http://screaming3d.com/pics/misc/civic_oil.gif))

At this time of the morning, I don't have the motivation to search for what test it was, but there WAS an oil test in one of the magazines a year or so ago. They tested automotive oils and motorcycle oils and their findings were enlightening.

1. They found that there is a difference between motorcycle oils and automotive oils. For example, the Mobil 1 motorcycle oil had some more of some additives and less of others, and their analysis concluded that the additive mix for the motorcycle was, in fact, more suited for the motorcycle.

2. After 1500 miles, the one and only synthetic they tested was the ONLY oil that retained 80% of it's "effectiveness", that meaning viscosity and lubricating properties.

Ok, so they determined that a synthetic oil has got to be a better way to go. I'll go with that. As far as the motorcycle vs auto oil, Mobil 1 auto oil is around 6 bucks a quart and Mobil 1 Motorcycle oil is around 8 bucks a quart (both prices from AutoZone), the total difference for an oil change is around 10 bucks, trivial $$$ really.

Now, as far as the oil test that skier is listing, I think the only relevant test is the Honda oil test. Both other samples are with oil that is not within the spec the bike is supposed to run, either the wrong weight or auto oil, or in the case of the first oil listed, both. However, I do agree with your idea of changing the oil often. I mean, when was the last time you heard of someone causing damage because they changed their oil too often?

just change the oil religiously thats all i do :D

At this time of the morning, I don't have the motivation to search for what test it was, but there WAS an oil test in one of the magazines a year or so ago. They tested automotive oils and motorcycle oils and their findings were enlightening.

1. They found that there is a difference between motorcycle oils and automotive oils. For example, the Mobil 1 motorcycle oil had some more of some additives and less of others, and their analysis concluded that the additive mix for the motorcycle was, in fact, more suited for the motorcycle.

2. After 1500 miles, the one and only synthetic they tested was the ONLY oil that retained 80% of it's "effectiveness", that meaning viscosity and lubricating properties.

Ok, so they determined that a synthetic oil has got to be a better way to go. I'll go with that. As far as the motorcycle vs auto oil, Mobil 1 auto oil is around 6 bucks a quart and Mobil 1 Motorcycle oil is around 8 bucks a quart (both prices from AutoZone), the total difference for an oil change is around 10 bucks, trivial $$$ really.

Now, as far as the oil test that skier is listing, I think the only relevant test is the Honda oil test. Both other samples are with oil that is not within the spec the bike is supposed to run, either the wrong weight or auto oil, or in the case of the first oil listed, both. However, I do agree with your idea of changing the oil often. I mean, when was the last time you heard of someone causing damage because they changed their oil too often?

Linky?? I would love to see this article.

And I've seen a ton of stripped out drain plugs from changing too often :P

Ok, finally awake enough to google. Here it is.

Part 1

http://www.sportrider.com/tech/146_0308_oil/

Part 2

http://www.sportrider.com/tech/146_0310_oil/

At this time of the morning, I don't have the motivation to search for what test it was, but there WAS an oil test in one of the magazines a year or so ago. They tested automotive oils and motorcycle oils and their findings were enlightening.

1. They found that there is a difference between motorcycle oils and automotive oils. For example, the Mobil 1 motorcycle oil had some more of some additives and less of others, and their analysis concluded that the additive mix for the motorcycle was, in fact, more suited for the motorcycle.

2. After 1500 miles, the one and only synthetic they tested was the ONLY oil that retained 80% of it's "effectiveness", that meaning viscosity and lubricating properties.

Ok, so they determined that a synthetic oil has got to be a better way to go. I'll go with that. As far as the motorcycle vs auto oil, Mobil 1 auto oil is around 6 bucks a quart and Mobil 1 Motorcycle oil is around 8 bucks a quart (both prices from AutoZone), the total difference for an oil change is around 10 bucks, trivial $$$ really.

Now, as far as the oil test that skier is listing, I think the only relevant test is the Honda oil test. Both other samples are with oil that is not within the spec the bike is supposed to run, either the wrong weight or auto oil, or in the case of the first oil listed, both. However, I do agree with your idea of changing the oil often. I mean, when was the last time you heard of someone causing damage because they changed their oil too often?

Linky?? I would love to see this article.

And I've seen a ton of stripped out drain plugs from changing too often :P

http://www.fumotovalve.com/

Now, as far as the oil test that skier is listing, I think the only relevant test is the Honda oil test. Both other samples are with oil that is not within the spec the bike is supposed to run, either the wrong weight or auto oil, or in the case of the first oil listed, both. However, I do agree with your idea of changing the oil often. I mean, when was the last time you heard of someone causing damage because they changed their oil too often?

I disagree - the tests show motorcycle-specific oil lasts just as long as car oil in our bikes. If these $2 a quart oils protect my motor and transmission just as well as the current pricey AMSOIL motorcycle oil in it now, I don't see the point in dropping an extra $20 or $30 per oil change.

Well, see, there's the rub. The owner's manual says to use 10w40, JASO MA rated motorcycle oil. If you use vegiee oil in the crankcase and it proves to be 100% better for you, then good for you. However, for the $8 a quart it cost me to use synthetic motorcycle oil of the spec that HONDA wants, why not? I mean, really, whatcha savin' here, about 24 bucks an oil change?

But to each their own.

Well, see, there's the rub. The owner's manual says to use 10w40, JASO MA rated motorcycle oil. If you use vegiee oil in the crankcase and it proves to be 100% better for you, then good for you. However, for the $8 a quart it cost me to use synthetic motorcycle oil of the spec that HONDA wants, why not? I mean, really, whatcha savin' here, about 24 bucks an oil change?

But to each their own.

The manual for my '04 599 says to use:

API SG or higher except oils labeled as energy conserving on the circular API service label, SAE 10W-40, JASO T 903 standard MA, Pro Honda GN4 or HP4 (without molybdenum additves) 4 stroke oil (USA & Canada) or Honda 4-stroke oil (Canada only), or an equivalent motorcycle oil.

The only reason Castrol GTX 10W-40 doesn't fit this description is because it's a car oil. However, looking at the additive packages between the car and bike oils I've tested, there's not a heck of a lot of difference. Certainly not enough to warrant the surcharge of Honda's oil!

As for saving money, if I save $20 an oil change (easily done) and I keep my bike for 60,000 miles as I plan to, I'll save over $400 in the life of the bike that can be spent on tires, chain and sprockets and other items that will wear out.

I wouldn't run Honda oil either as it's a ripoff. As far as the car vs motorcycle oil and the synthetic vs dino, it's all opinion. I will say that JASO MA spec is from the motorcycle manufacturers. It may very well be there just to pad their pocket, but I doubt it.

Mobil 1 and Mobil 1 MXT are distinctly different, as shown in the test that I posted the link to. Someone at Mobil 1 decided that the additive difference was warranted for a reason.

We have a saying in the military...when it's in black and white, it's right. Honda does spec the JASO MA and that's what I will recommend running. As I stated previously, who am I to argue with Honda.

As far as 20 bucks an oil change, I wouldn't run anything but Mobil 1 anyway, and the JASO MA rated Mobil 1 MTX 10W40 meets the spec and is only 2 or 3 bucks a quart more than automotive Mobil 1 . Yes, expensive oil, but for the insurance and piece of mind it provides to me, it's cheap.

Hell, I have spend THOUSANDS on safety equipment over the last 15 years that I have yet to use. Who am I to bitch about 12 bucks an oil change. If I am that hard up, I figure it's time to ditch the bike and drive the cage full time.

We have a saying in the military...when it's in black and white, it's right.

I figure if it looks like a duck, quacks like a duck and acts like a duck, it's a duck. GTX fills every spec Honda calls for in the manual except it's not branded as a motorcycle oil. Good enough for me!

This is about as far as I'm willing to debate oil again, as long as people realize they need to stay on top of changing it! Shoot, you probably could run vegetable oil in your bike and it'd be fine for thousands of miles if you change it often enough.


Yes, expensive oil, but for the insurance and piece of mind it provides to me, it's cheap.

I'd be worried if you're finding chunks of brain matter in that oil. :shock:

Thanks guys for all the pertinent information, after careful consideration, I have made my decision

http://www.mobiloil.com/USA-English/MotorOil/Oils/Mobil1_Racing_4T_10W-40.aspx

The 4T is all new stuff. I saw it at the store the other day beside the MX4T 10W40 from Mobil 1, which is what I use. I might give it a go next time. Great choice.

BTW, they should have it at AutoZone.

I recently changed to Amsoil and i swear the motor sounds different when starting, sounds like it spins faster? Anyone else?

I went with Amsoil in both of my bikes on the last oil change. I'm confident that the oil is as good as billed. The main reason that I switched is that you can go more miles between oil changes. I can't tell if the bike is smoother or not. My Honda VT1100 may show improvement in vibration. Both bikes are down a bit in gas milage and I wonder if the viscosity is different even though it is 10w40. I have 30,000 on the cruiser and 15,000 on the Hornet. That may have something to do with it. I get almost 50 mpg on both and got 50plus previously.

I recently changed to Amsoil and i swear the motor sounds different when starting, sounds like it spins faster? Anyone else?

I got the same thing when I switched to Amsoil in my bike. I've been an Amsoil guy for about 10 years in my cars. Run 100% Amsoil synthetic fluids in all of my cars, oil, tranny, differential, radiator, etc. I'm a very happy Amsoil user and don't plan on using anything else.

So what would you say is the Diff. with Amsoil thats causing it to sound different? a diff. Viscosity like tomacana said maybe? If it seems to spin faster at startup, it would have to be 1) thinner or 2) slicker...dont know

So what would you say is the Diff. with Amsoil thats causing it to sound different? a diff. Viscosity like tomacana said maybe? If it seems to spin faster at startup, it would have to be 1) thinner or 2) slicker...dont know

It's certainly not a viscosity difference. Remember the numbers in the oil specifications? "10W-40" and the like? It means it has a certain viscosity at the cold/winter/W rating and it has one when warmed up (the one without a label).

Out of the bottle, a 10W-40 dino oil will flow exactly the same as a 10W-40 bottle of Royal Purple, AMSOIL, vegetable oil, etc...

However, the synthetics are generally better at keeping this viscosity than dino oils.

My $0.02 after running AMSOIL for 2500 miles: Feels the same to me. Still clunks when dropping into first, the engine didn't "pick up 15 MPH on the top end" like someone told me on a different board,

I ordered another two gallons of it to run another 5,000 miles with the oil, but I have a feeling I'll be back to good ol' Castrol GTX soon enough. :)

Rgr that. I was kinda implying that maybe Amsoil or the Castrol isn't EXACTLY 10w-40 .. or maybe something was just a little bit diff. with the two.. And I'm all for using something more expensive even if the only difference is that I THINK its better...... How I feel on my bike means as much to me as anything....

How I feel on my bike means as much to me as anything....

It almost certainly effects a ride more than what's splashing around in the engine. :)

As far as the car vs motorcycle oil and the synthetic vs dino, it's all opinion. I will say that JASO MA spec is from the motorcycle manufacturers. It may very well be there just to pad their pocket, but I doubt it.

The car vs. motorcycle oil isn't about opinion, it is about additives. Twenty years ago it didn't make a difference, but modern automobile oils have energy saving additives - friction modifiers. These additives negatively affect the wet clutches in motorcycles that share crankcase oil and transmission oil, like the Hornet. The JASO MA spec, among other things, specifies an oil devoid of these friction modifiers.

The bottom line is, it is not so much the engine, but the clutch that doesn't like automobile oil.

As far as the car vs motorcycle oil and the synthetic vs dino, it's all opinion. I will say that JASO MA spec is from the motorcycle manufacturers. It may very well be there just to pad their pocket, but I doubt it.

The car vs. motorcycle oil isn't about opinion, it is about additives. Twenty years ago it didn't make a difference, but modern automobile oils have energy saving additives - friction modifiers. These additives negatively affect the wet clutches in motorcycles that share crankcase oil and transmission oil, like the Hornet. The JASO MA spec, among other things, specifies an oil devoid of these friction modifiers.

The bottom line is, it is not so much the engine, but the clutch that doesn't like automobile oil.

The heavier weight oils usually don't have the "energy conserving" label on them. I've yet to see a 10W-40 or 20W-50 oil that has that part of the donut label filled in.

To compound things, though, the latest API oil standard, SM, allows for friction modifiers to be present without having the "energy conserving" label. That said, I haven't had any problems with it.

Just remember, SJ, SL, and SM oils all have way less zinc then the older oils had, and zinc is very good for your camshaft and tappets, as well as other extreme pressure situations, like inside the transmission.

Just remember, SJ, SL, and SM oils all have way less zinc then the older oils had, and zinc is very good for your camshaft and tappets, as well as other extreme pressure situations, like inside the transmission.

Even though I just paid $8.99/quart for Mobile 1 4T, I did see a four quart jug of Suzuki 10W-40 JASO MA dino oil for $12.99 at a dealer the other day. At that price, with all the factors mentioned regarding additives, there is not a huge reason not to buy bike-specific oil.

Just remember, SJ, SL, and SM oils all have way less zinc then the older oils had, and zinc is very good for your camshaft and tappets, as well as other extreme pressure situations, like inside the transmission.

For what it's worth, Valvoline seems have have a significant amount of zinc in it compared to Castrol GTX, Mobil 1 and Pennzoil. It also has more than Honda GN-4.

I just checked...I'm getting plenty of zinc in my multi vitamin... :gtfo

Guess for me, I don't want to read labels and worry about zinc and have even the remotest possibility of later being sad because I grabbed the wrong oil trying to save $20 on a every one or two year service interval...

I just pop in the Honda place, ask for a filter and pick up the Honda race oil while I'm there (and usually two or three other items I have no need for :wink: ) This last time I used the Synth stuff...the old school shop owner said I was wasting my money and could tell no difference in feel after...

Guess for me, I don't want to read labels ..

How do you know what to eat and what not to eat inside a pack of beef jerky? :)

Beef jerky is easy...you don't need to worry! The "beef", plastic and box are equally (in)digestible so no need to differentiate.

Chomp away :thumbsup

We're more concerned about that little bag of silicone beads designed to absorb any excess water in there. That stuff'll fuck you right up.

Really? :shock:

You'll be OK if it's Synthetic Silicone... 8)

Just remember... there are a $hit ton of cars around that have 100's of thousands of miles on them on Dino oil. Synthetic hasnt been around long enough to prove itself that mush better.

Basically.. either way, as long as you choose the correct viscosity motorcycle oil and change it regularly, your bike will run great.

yup you don't get 5 times the mileage from syn but pay 5 times the price

Well, see, there's the rub. The owner's manual says to use 10w40, JASO MA rated motorcycle oil. If you use vegiee oil in the crankcase and it proves to be 100% better for you, then good for you. However, for the $8 a quart it cost me to use synthetic motorcycle oil of the spec that HONDA wants, why not? I mean, really, whatcha savin' here, about 24 bucks an oil change?

But to each their own.

The manual for my '04 599 says to use:

API SG or higher except oils labeled as energy conserving on the circular API service label, SAE 10W-40, JASO T 903 standard MA, Pro Honda GN4 or HP4 (without molybdenum additves) 4 stroke oil (USA & Canada) or Honda 4-stroke oil (Canada only), or an equivalent motorcycle oil.

The only reason Castrol GTX 10W-40 doesn't fit this description is because it's a car oil. However, looking at the additive packages between the car and bike oils I've tested, there's not a heck of a lot of difference. Certainly not enough to warrant the surcharge of Honda's oil!

As for saving money, if I save $20 an oil change (easily done) and I keep my bike for 60,000 miles as I plan to, I'll save over $400 in the life of the bike that can be spent on tires, chain and sprockets and other items that will wear out.

castrol gtx is acceptable cause it meets the API standard of SG or higher which honda also says is okay (pg 104 in the 2006 owners manual)

I recently changed to Amsoil and i swear the motor sounds different when starting, sounds like it spins faster? Anyone else?

the motor always sounds different when you put in fresh oil

I use 20w-50 dino that meets API SG or higher, why 20-50 cause it last longer, as oil breaks down the viscosity lowers like others mention in their oil analysis test shows 10-40 becoming 10-30 after a few thousand miles, and dino oil can still be had for ~$1 per bottle/quart while say mobil 1 mx oil is like $8 per bottle but will it make my motor last 8 times longer or will the oil itself last 8 times longer? I think not....I change my oil every 6months, I'm still only gonna change the filter every 8kmiles like the manual says, why 6months cause I don't put that many miles on my bike (I know shame on me for not riding enough) and their is still build up in the oil no matter if you ride the bike or not

but honda says use 10-40 for a reason as well knowing that the oil will thin out with use...they have an acceptable limit to what the oil can thin out to and for the ease of tracking they use a mileage interval (8k miles) and/or time interval (12months) which ever comes first...so for certain I think we all change our oil too soon

I always wonder if y'all put this much thought into other things in yer lives... Like, can only imagine standing in front of the toothpaste section... Or the "personal lubricant" internal dialog :lol:

I just changed tires and oil this week. One good thing about an oil change?
5 MPG improvement on gas mileage. Lance was up here in June and we both had to gas up with about 150 miles on a tank. It typically took 3.3 gallons to top off the tank with 150-155 miles. I got 195 miles yesterday as I hit reserve. That improved my mileage about 5 mpg. The improved mileage doesn't necessarily last much over a tank or two or it didn't last time and that is with Amsoil synthetic.

The new tires may have helped with the mileage. I now have the Avon Storms on front and rear. The Pirelli Stradas were pretty good except that the front tire was noisy. If I was on pavement with a rough surface, it sounded as if something was wrong with the front end.

One last note. My bike wouldn't start with the engine in gear even with the clutch pulled in. Started in neutral and I expected it to die when I shifted into 1st. It didn't. The problem was that when I washed the bike last, I bumped the connections on clutch lever. The result was that the start circuit sees the clutch as engaged and will not let the engine start in gear and once started the run circuit ignores the clutch switch.

Well, I've gone through a few oil changes and analysis reports. Looks like AMSOIL's motorcycle oil does indeed last quite a bit longer than the previous oils I've had in motorcycles. From the oils I've run through the bike, AMSOIL lasted longer than: Castrol GTX 10W-40, Mobil 1 10W-30 and Honda GN4 10W-40.

At just under 4,000 miles on the last run of AMSOIL, it looked better than 2,500 miles on the oils listed above.

I guess I'm converted and am content with shelling out a ridiculous amount of money per oil change. :thumbsup

Trying some Rotella diesel oil the SV650 guys rave about may be next, but who knows.

Skier...Can I request you do the HP4 and the HP4M next? :mrgreen:

The GN4 is their standard oil so it isn't really fair to compare that in there with Amsoil or Mobil1...

Skier...Can I request you do the HP4 and the HP4M next? :mrgreen:

The GN4 is their standard oil so it isn't really fair to compare that in there with Amsoil or Mobil1...

Sure, send me a gallon of each and I'll put some miles on them... for science.

Sure...
OK, next oil change let me know...I'll kick you the bucks for the HP4 oil...for science....just let me know when your changing oil :thumbsup

But you gotta start a nice neat orderly thread and list all your previous data and keep adding to it. Charts reports and all that :wink:

Deal?

ooooo I'm likeing this... This thread is finally getting juicy...I like it when we get "Real World" Info like this....

That is, If he agree's :shock:

I'll scare up some moly-free HP4 and run some miles on that sometime. Probably next season or so, I don't have any big trips planned for the rest of this season.

I also played with some data to graph and how. I'll get around to this sometime Real Soon (read: don't hold your breath! :) ).

I recently changed to Amsoil and i swear the motor sounds different when starting, sounds like it spins faster? Anyone else?

It's possible. Historically, the biggest benefit to synthetics is at cold start. I used to use Castrol 20W50 in my VW rabbit back in college. I changed my mind when I added oil one cool morning and it poured out of the bottle like honey. I would guess that the Amsoil still pours and pumps very nicely at that temperature. Oh, and your battery is probably a little stronger in warmer weather than it was earlier in the spring.