Ihookem, the problem is that there are few PAOs left on the market anymore since Katrina. A lot of production was taken off of the market with down refineries. Most reformulated and because the ethylene gas used to make it is getting harder to find and expensive, they just never went back to it. Most are using a high VI splash at best with the Gp III/+ severely hydrocracked oils making the biggest percentage of the base oil. If you just wanted to stay with Amsoil, the Heavy Duty 10w-30 diesel oil is a dandy and we recommend it to a lot of fleets where maintenance down time is money. The difference in cold start condition is only 7F and there's more differences between engines than that. Otherwise the Delo is right there with it for cold start conditions. With the newer specs on the oils there's little in the way of deposits allowed like oils of just a few years ago. The newer CI+4 and CJ oils are very clean in that regards. There is a hairs more solvency in a PAO than a Gp III/+ but it's not enough to make a real difference. AVOID any of the engine cleaners as most are solvent based and strip lubrication. About the only one I recommend and it's expensive is Auto-Rx. It's a lanolin ester similar to the esters used in some of the high mileage oils. It's a fabulous cleaner and will help with leaking seals that have a slow drip but it's like anything else, it can only do so much. But it is a good, but slow cleaner and seal conditioner. If you go to their website, skip the advertising BS, it's a cleaner and seal conditioner, nothing more. Maybe one of these days Green Technologies will really get their act together and put their ester based diesel rated oils out. The G-Oil is a fabulous cleaner and a decent oil especially when it's almost free with their coupons. If you ever see it, there's the oil for cleaning an engine. Their gas formulation, in my opinion, is not a premium price formulation- it's ho-hum at best but the base oil has tremendous solvency and as such will be great for cleaning.
In regards to transmission fluids. Mecon V, Dextron VI are the same now. GM and Ford have been swapping transmission technologies for a couple of years and the fluids are the same. Both, and including ATF+3, are synthetic Gp III based oils regardless of brand as long as it wears one of the big three certifications on the bottle. Buying and paying for a branded label synthetic buys you nothing but a lighter wallet. ATFs have a frictional co-efficient that is proprietary and the maker does not have to share that info with the after market blenders. I'd suggest changing ATF every 30,000 miles and use nothing but the auto makers brand fluid, like GM Dextron, Ford Mercon, Dodge ATF+3 and skip brands like Mobil, Amsoil, Valvoline, etc. For Charles P, I'd get the fluid changed at yer earliest convenience if you want long transmission life.
In regards to engines that sit. I have a garage full of old cars. One, for an example, is a one owner 1989 LSC with a 5.0 making a factory 325 HP. It's a fairly rare care or I guess I should say, rare engine from Ford. It's a garage queen and has never seen rain. The speedo says it has 34,000 miles on the clock.Obviously the car looks, drives, and smells new. The current oil in it has less than a 1000 miles on it and is 5 years old now. I pull it every year and do spectroscopy on it to make sure something hasn't gone wrong. It's still fine with decent wear metals, low shearing, etc. The oil is Chevron Supreme and is a blend 5w-30. You get the best of all of the characteristics of the base oils with the blends. Low corrosion, good lubricity, stable with no additive fallout, just good oil. If you have an engine that sits a lot, avoid any of the synthetics. Otherwise the probabilistic are high you'll see corrosion go thru the roof. All motor oils are a synergistic blend. ALL base oils have good and bad characteristics. Synthetics at one time were great at high heat but the dino based oils have caught up. Synthetics are not prone to staying on the parts when the engine shuts down. They employ tackifiers for this but it can only do so much over time. Some synthetics are built to be polar attracted to the parts to solve the issue but then the film strength is so great that they have to use something like alkylated naphthalene to cut it otherwise the additive package can't get in to its job and wear is increased. With the blends, these problems go away as the best of all of the base oils come already in the bottle.
I get asked everyday it seems as to which is the best oil. The best oil out there is API certified of the correct viscosity for your engine and fresh. So pick a brand, don't pay a lot for it, make sure it meets the auto makers certifications, sit back and enjoy the ride. You trusted the maker enough to buy his product, trust him enough that he knows what is the best for your engine. He engineered it, built it, and designed the lube system. It stands to reason he knows more what's good for your engine than anybody.
