What grade on my 2SS?

[SA CHEVY]

Well my first oil change isn't going to be for a little while but figured I'd stock up now (excited for that first change). I've enjoyed everyones bickering in the past threads that put RP & Amsoil head to head and wanted to thank all those involved for the entertainment But on a more serious note, what grade of RP are you guys running that have the L99? Here in Bakersfield with summer creeping up we see temperatures usually in the high 90's to mid 100's just about every day from mid-June until late August so I needed that in consideration with my oil. Let me know what you guys think would work best here on this little chunk of the sun to keep my beast in tip-top shape!!

[ron10]

i will be using exactly what the book says.5W-30 synthetic.

[AZ5G]

Amsoil 0-30w here in AZ...Did 2 oil changes with Mobil 1, 1500/300 then switched..Engine is quiter and very happy....DD

[SA CHEVY]

I've been hearing people throw 0-30w out there but is that a little too light?

[wylde1]

it just pours lighter. it's actually pouring at the same viscosity (or very close) to what it is when it's hot in your engine.

WARNING: TECHNICAL EXPLANATION TO FOLLOW haha

The first number in the oil grade (0w, 5w, 10w, 20w) is related to the oils temperature dynamics. Meaning the higher the number, the more the viscosity changes with temperature. SAE ratings for these numbers test the viscosity at 40*C and 100*C to build a viscosity curve. If comparing 2 oils, say a 0w-30 and 20w-30. the 0w maintains a nearly flat line (i.e. constant viscosity) over the course of the desired temperature range. Whereas the 20w will look more like a rising (45 degree) line/curve, meaning it's viscosity will change greatly over the range. The two lines do intersect however, and that is the ideal operating point which has to do with the 2nd number.

for SAE testing the oil must maintain certain viscositys over certain windows of temperatures. The 2nd number (20, 30, 40) describes the viscosity window. I don't remember the exact numbers off hand, they're probably available in a search of the google machine, but essentially viscosity goes up with these numbers (think thicker).

So what does this mean for your car? when an engineer designs the engine, the bearing size and clearance determines the size of the hydrodynamic wedge needed to keep the crank/rods working properly. The viscosity of the oil determines the size of the wedge it makes, and the oil is chosen on this basis. so if your manual calls for XXw-30 NEVER AND I MEAN NEVER change the second number. 5w-20 and 5w-30 are NOT the same thing. However as long as you keep the 2nd number the same the choice of the first number is entirely up to you, based on price and what kind of climate you live in.

here's the part that alot of people can't get their head around. for the reasons described above... at operating temperature, your engine can NOT tell the difference between 0W-30 and 20W-30. (ignoring additives, which are a whole different discussion that have more to do with longevity of your engine than actual operation) The main difference between the 2 is the viscosity on a cold start. with the 0w the viscosity will be the same as at running temp, with 20w it will be much thicker than running temp. (and therefore your bearings are not running the size of wedge they were designed for)

to sum it all up, if you can afford it, put 0w-XX (x's depend on your specific vehicle, some hondas and fords use 20, most chevs use 30) in everything you own. the 0w is only acieveable through a full synthetic so it is usually expensive. Beyond that get the lowest first number you can afford while keeping the 2nd number the same as the manual recommends.

NOTE* in the interest of keeping this readable and not a technical paper I left a few things out but this is sort of a birds eye view and stuff that everyone should know when choosing an oil.


And remember you get what you pay for. If you see an oil advertised as Synthetic for $4/L, put up red flags. The prices are slowly coming down, and the synth-blends are not too bad. but for a full synthetic PAO you will pay roughly $11-$12 per litre, anything less read the label carefully because your probably missing something.

[SA CHEVY]

Thanks for the good info wylde1. I may just side with AZ5G then and go with the 0w-30 because I have heard people saying their motors run a lot quieter.

[wylde1]

If you can afford it that is IMHO the way to go.

from the info I've found, Amsoil 5w-30 and 10w-30 use a PAO (group IV) base stock, and the 0w-30 uses a blend of PAO and Polyolester (group V) base stock. So it's made from the top level ingredients available. Even though it's "blended" it's still with two full synthetic bases. When you hear the term "Synthetic Blend" on another oil it only has to contain 30% synthetic base, the rest is mineral oil. The reason people say their engines are alot quieter when running this type of oil is the base stock, plain and simple. The high quality synthetics offer the lowest friction while maintaining film strength

I don't in any way represent Amsoil haha there are other companys that make their full synthetics from this base stock (in fact almost all synthetic base stocks come from 2 suppliers and are bought by these brand names) But that's the kind of stuff you need to look for. Watch out for posers.

FOR INSTANCE: I have scoured Royal Purples site and can find no mention of the TYPE of base stock they use. On their MSDS sheed it only says "synthetic" base stock. which IMHO means they are using grade III or lower base stocks and pushing their "Synerlec" additive package as the difference maker. which is typically 10-20% of the fluid volume. yes the additives make a big difference.. but wouldn't you think the other 80-90% of the volume would be a big deal as well?

I'm not saying RP products are bad, some people use them and love them, but I don't like the fact that it looks like they're hiding something from me. Seems like a Slick 50 case to me.

[wylde1]

haha the more I read that the more it sounds like an Amsoil commercial, but as an example, Mobil 1 also used PAO's

penzoil, castrol and valvoline do not


of course there is always one more option.... use a cheaper oil and change it more often. Really you'll probably never tell the difference doing that, but I like knowing that at all times I'm getting the best products I can afford.

[SSMickey]

www.bobistheoilguy.com
All you need to know about oil and then some! Lot's and I mean lot's of good info on the site.

[SA CHEVY]

Originally Posted by wylde1

haha the more I read that the more it sounds like an Amsoil commercial, but as an example, Mobil 1 also used PAO's

penzoil, castrol and valvoline do not


of course there is always one more option.... use a cheaper oil and change it more often. Really you'll probably never tell the difference doing that, but I like knowing that at all times I'm getting the best products I can afford.

Haha do we have an Amsoil rep on our hands??

No I wont be sparing any expenses on this car, I want it running the best it can get all the time. If 0w-30 will be the best thing for it, then 0w-30 is what she will get!