Finally located some 0w20 synthetic engine oil
 

For any members north of the 49th, my local Canadian Tire never seemed to stock any 0w20, so I've been running 5w20 most of the time. None of the other auto parts stores in town had 0w20 either (and I wasn't interested in paying Honda or Toyota dealer prices for it).

For some reason, I asked at the counter last visit, and they looked in the computer. There's a "do not re-order" note on the product (it's Pennzoil), due to poor sales, I guess.

But he saw that a store in another town (Kemptville, ON) had some, so I stopped in on my way to visit my sister & family on the weekend and bought 3 oil changes worth.

They were on sale too - because so few people buy them. They were dusty. $6 and change/litre.

$6/L isn't bad. Couldn't you find an AMSOIL dealer in the area? Most places seem to have one, commercial or private, and I know I've seen 0w20 from them. $35.85/Gal direct from them. Sure it's closer to $9/L, but I know I've run their 0w30 for 6000 miles with only a filter change at 3000miles (plus a top up) and the oil was still good.

I'm biased though, having grown up using AMSOIL in everything from snowblower to motorhome.

I hadn't even heard of AMSOIL until members on EcoModder mentioned it. A quick search shows there's no dealer near by. 100 km away is the closest.

You'll quickly locate any oil leaks! Not recommended for old Subarus.

Can someone explain the pros and cons of using this oil in a car that the manufacturer recommends 10W30? What kind of gain could be expected? What possible complications, malfunctions, or damage could occur? BTW, I am currently using Mobil1 10W30 and saw a 5 mpg increase. I replace my oil every 6,000 to 10,000 miles (mostly interstate).

I didn't notice a performance or mileage difference going from Mobil 1 5W-30 to the 0W in my EA81 Subaru. The stuff is so light, it pours like water and, with me and my bad rear main seal, leaked accordingly.

complications are more numerous going from 10w to 0w. the first and most annoying one will likely be it will leak all over the place for a substantial amount of time unless you replace all the seals. The seals respond to the oil and seat with it, so if you all of a sudden switch it can leak through the seals(this happened/happens to me).

Other problems might arise if the oil is too light for your engine. I kind of doubt that would be a problem but it would be much easier to "burn up" a 0w pan than a 10w. By burn up I mean starting the car and almost immediately going to redline, it doesn't give the oil time to get up to the 30 weight of heavy duty/performance operating temperature. That said unless you have a turbo or a supercharger this is somewhat hard to do because most cars don't have the kind of HP to get to redline before the oil gets warm(in between 0-30 weight but not hot(30W)). You of course could if you jumped in your car and stopped the accelerator in first gear, but I don't really know anyone who does this. Usually people stomp the accelerator but shift before it gets above ~3400 and do that until they are out of gears and then let it go above 4K rpm where the danger exists for the engine oil.

Your transmission on the other hand won't have this luxury, but you aren't asking about changing that. It is more susceptible because its likely to still be cold when you start shifting hard and even when you get up to speed and may not protect the gears properly.

theunchosen - Thanks! that is the info that I was looking for. I will not be making the switch since I don't want to invest in new seals. As for my manual trans, I was just going to put in redline this summer when I replace it.

Depending on the mileage you might still be ok. Your car is an 05. . .mine is a 93 lol obviously that oil has had some serious time to work its way into and round the seals. With better cars it may not be an issue at all(I guess I mean newer cars). Usually though whenever you switch weights you get some leakage the quality of the car determines how much. Mine's pretty old and the seals were accustomed to 10w when I dropped to 5W30.

The leaking is also hard to measure since I also have a slight warp in my oil pan where a mechanic missed my reinforced structure and put the jack on the oil pan. The washer and bolt don't sit completely flush against the pan anymore so it drips a tiny amount(over a 3000 mile swap out its usually a quart low(it takes two months)). I countered this after the first swap and add a full quart about halfway between oil changes.

I certainly do not know about economy; but once upon a time we poured out 10w30 dino oil from a 7mgte, poured in 0wt 10 and consistently gained 10 whp.
The Motor in question had about 150k on it with original seals, it didn't leak until the pcv plugged up and blew every seal out of the motor around 200k.

Leaking is a hard thing to call; but I can't think of a reason that the leak wouldn't shrink back to its invisible state (which will eventually grow and get blamed on your thin oil experiment) if you switch back to the thicker oil.