I believe it was around 2001 when car manufacturers started using W20 weight oil (Honda and Ford) so the oil is nothing new, I've seen it even at Walmart. As far as difference between 5W20 and 0W20 I don't think it matters. If I remember correctly the first number is for cold oil, so it's only for the first minute or so after first engine start up it has any meaning at all, once the oil is warm it is the same weight of 20 and 0W20 could only make difference in very cold weather.

 

I think that most people are concerned about the 0W20 vs 5W20 because the ICE stops and starts so often during driving. Thinner oil may, and I only say may, help to lub the ICE during these frequent stops and starts.

 

Only when that oil is cold, there is a difference, once the engine starts and runs for a while the oil temperature (and catalytic converter) will be kept at operating temperature and if it goes bellow, the engine will restart even when parked, therefore IMO there should be no difference. If Toyota was very concerned about lubrication during frequent starts and stops, they could pre lubricate the engine with electric oil pump. The bottom line is, TCH has as many cold starts as any other regular car, everything else is warm starts and thats the number after W that counts here and it's the same for both. I'm also not sure at what point the oil would be too thin, if you run 0W20 in the engine not designed for it, it could damage that engine.

 

I did some reading on the subject. The 0 part of the oil is for cold starting the engine. The thin oil gets up into the valve area quicker. The 20 means the oil has the ability to thicken and do the work of any quality 20 weight oil. It may not thicken exactly as much as a straight 20 weight oil. The synthetic would be the better oil over the dino. Thats due to it not breaking down under extreme heat.

 

Rburt, you are close, but the oil does not actually thicken. A 0 wt oil is just a 0 wt period. The additives in the oil make it protect similar to a 20wt, but the oil itself never thickens.
The W in 0w20 actually stands for "winter". That's right, in "winter" the oil flows of a 0 wt and when hot can simulate or protect like a 20wt.

08FEH

 

So I called Toyota Of Kirkland and told them I had purchased the 0w-20 oil in the past twice (for my 5k and 10k oil changes) and told them I paid about $4.76/qt. I also remember that they tried to charge me $6.49 when I last bought it but they "found their mistake" and was also charging the "labor" instead of just the part. Anyways, they offered to sell it to me for $4.58/qt. I quickly ran over there and bough 10qts and 2 oil filters

 

That's the regular price I'm paying at my dealer and that's the least expensive price for synthetic oil I can find anywhere, so I always buy 10-15 quarts also. BTW your car takes something close to 4.5 - 4 and 3/4 quarts, so after 2 or 3 changes you should have 1 quart extra. I know they had some problems with oil foaming when overfilled in Prius, didn't hear anything about TCH, but I try not to overfill the oil anyway.

 

Pete4: I agree with most everything you said, but if you don't mind just try an experiment for me. Let your TCH get cold, exm. overnight, get in your TCH and hit the start button, leave it in park, after a few seconds it will start, continue to let it run and it will shut back down in about a minute, ICE still cold, now place in it in gear and the ICE will restart, still cold. Mine works like this in town at stops lights before the ICE warms-up as well.

 

I don't know, my car doesn't shutdown until the temp. gauge is at least halfway between cold and warm, and with summer temperatures into 90F and closed thermostat, it may take as short as 1 min or so, but in Winter it takes much longer. Low oil viscosity( 0 in 0W20) is measured at 0 F, (That's minus 18 C, for our Canadian readers) and hot oil viscosity is measured at 210 F (close to boiling point of water). If I was going to make wild estimate from the dashboard gauge, the engine won't shutdown until it is close to about 140F and normally runs at 160-180F. I would think , except for the first start , the engine oil temperature is always pretty warm and runs closer to hot viscosity rating than cold, except for that first crank.

 

You are correct. I got some of the information from some older forms talking about motorcycle oils.

I used to drag race in the late 50's and early 60's. I remember when the high detergent oils became popular. Oil changes went up to 2000 and 3000 miles. The detergent helps to reduce friction. That was over 40 years ago. Thats lots of years to improve the detergent. I bought my first quart of pure synthetic oil in the mid 70's. It was called EON from a Houston manufacture. Amzoil (now Amsoil)? came on the scene I think in the early 70's. I did not hear about Amzoil till the early 80's.

Remember the NASCAR, INDY 500 and NHRA drag race engine failures about 15 years ago. Now NASCAR and INDY cars are using synthetic oil. NHRA, the drag race officals requires all their nitro cars to use a special thicker Red Line synthetic oil.