Motorcraft 5w20 blend vs. 5w30 in a Prius

[dvancleve]

Howdy folks. I have run the Motorcraft 5w20 in my wife's Prius since the first oil change. I did use Motorcraft 5w30 blend a couple of times and didn't notice any difference in the operation of the car. The manual says 5w30 is "recommended" and 10w30 is the only alternative mentioned. I see now that Toyota has issued a few TSBs over the years allowing 0w20 and 5w20 oils for most models going back to 2000 or so, but the Prius is specifically excluded (says to stick with 5w30). I am in Phoenix, so it is very hot during the summer and rarely gets below 30degF ever. The car seems to get about 15K miles a year.

I have read that the MC 5w20 is more stable than most 5w30s and quite possibly higher viscosity by oil change time. I am past my powertrain warranty based on miles, but I wonder if I would be better off using a 5w30 oil. Is the MC 5w20 better than the MC 5w30? Are there other 5w20s that are just as good and might be cheaper? It has come close to doubling in price at Walmart in the years I have used it… Is there a 5w30 conventional or blend that would generally be less dough than the MC and better than average for a Prius (Miller cycle engine but starts and stops a lot)?

I tried searching for this stuff, but really didn't find anything...

Thanks, Doug

 

[bustednutz]

I'd stay with the 5W30 for that car. MC is a great oil. Price wise, it seems all oils are going up in price. Try to find a deal on sale of 5W30 synthetic, or blend.
In another week there will be all kinds of oil change specials at Autozone, or advanceautoparts, etc...
Check the rebates and promotion forums here.

 

[hardcore302]

all oil prices are going up.

 

[brentalan]

If the prius is excluded from 20 weights, I would follow the manufacturer suggestion.

 

[CATERHAM]

What year is your Prius?
The reason I ask is because the Toyota 0W-20 is back spec'd to the 2004 MY.

BTW a typical dino or dino blend 5W-20 will always be lighter than a 5W-30 dino even at the end of a long OCI.

If your Prius is a MY 2004 or later I'd try the Toyota 0W-20.
It's has a very unique formulation with a boatload of moly and is much lighter on start-up vs anything else available.
This oil was designed specifically for the Prius so why not try it.

 

[dvancleve]

CATERHAM, you appear to be correct. I found this, based on a screen capture from a different Prius thread: TGMO Application Chart. It appears that Toyota has decided 0w20, 5w20 and 5w30 are all appropriate for the Gen2 Prius. Should I stick with my no-longer-a-bargain Motorcraft 5w20 blend, go with some other 5w20 or go with a 5w30? No point in 0wAnything here in Phoenix... Doug

 

[dvancleve]

So I can use any 0w20 through 5w30 oil. I am out of powertrain warranty, what is a reasonable OCI? If I want to go for something like 7500 miles, about 2x a year, is a full synthetic the prudent choice or can any good blend (or even dino) do that? Am I correct in thinking there's no reason for 0wXX here in the desert?

Thanks again, Doug

 

[CATERHAM]

You can't get a 0W-XX that isn't predominately synthetic.
You'll have superior lubrication with a 0W-20 synthetic than a 5W-20 dino in the heat of an AZ summer.

One thing you haven't mentioned is how you drive your car, but assuming you drive your Prius for its intended use; i.e., lot of short trips with lots of stops and starts, there is nothing better than the Toyota 0W-20.
Having said that, the disadvantages of running a 5W-30 would be minimized during the heat of an AZ summer.

 

[dvancleve]

Thanks CATERHAM

My wife mostly drives the car, ~20mins at a shot 2-3x per day during the week and usually some pretty long drives on Saturday running our daughter all over the valley. We really don't speed much and I would say the car is driven pretty gently overall.

I am just guessing, but isn't the TGMO expensive? I can't imagine that pretty much any other synthetic wouldn't be cheaper but I could be wrong. Any suggestions on OCI? I am not really interested in doing any UOAs... Doug

 

[CATERHAM]

TGMO can be expensive but some Toyota and Lexus dealers will sell it down to $5/qt. It's also available in bulk from some dealers so they may fill up a 5qt jug for you for less.
Anyway shop around.
Toyota okays the OCI out ot 10,000 miles but I wouldn't go that long, say 7,500 miles.

 

[Oldwolf]

I have decided to use M1 0W30 in my Prius. Seem so like it as far as I can tell.