My experience using 5W-40 instead of 0W-20

Factory recommendation of 0W-20 -- for those who don't want to experiment with different viscosities. But I really like the 5W-30 Mobil 1. I'm sticking with it.

And what happen to that BuickGM poster???? He disappeared.

 

You should delete it because the post doesn't state that its out of date, a random lurker looking for info on here may just use it as a guide and follow it.

 

Sorry, too late to delete. I think Alan Clarke posted a more current chart.

Somebody wanted to know how my gas mileage is doing with the Mobil 5W-30? Doesn't seem to have affected the mpg at all. Here is another 500 mile tank. (the 4th or 5th?) I actually filled up at 504 miles, and put in 9 gallons exactly. Came out to 56 mpg calculated. (the DTE showed 60 miles left, plus some fumes ). AC always on, and in PWR mode. I can't complain about 56. I'll check the mpg again in a couple years.....
Just Drive It.

 

The dealer on your country recomends 5w40 because of hot climate, 1st owner of my prius used 10w40 liqui moly, i did on 10w40 close to 6k km then switched on 0w20 idemitsu and I get 8% less.

 

This is an old thread but interesting. It may also be off topic for me as I have a gen2 2007 Prius with 120k miles. The recommended oil for my car is SAE 5W-30 but I live in Florida and it gets very hot so, I was wondering if switching to a 5W-40 full synthetic or high mileage would be more beneficial for me during the summer months where is often is above 95-100 degrees F. Also, a lot of people here mention their favorite oil is Mobil 1 but what’s odd is the bottle doesn’t have the SAE wording. Thoughts?

 

0w-20 or 0w-16 oil? manual conflicts | Page 6 | PriusChat

I've done oil pressure testing on my 3rd gen Prius and fend that it gets up to 55 PSI at 3,000 RPMs and 160 f engine temp. 0w40 seems like the right oil for that engine. I used to use 5W-40 in my second gen Prius. I will tell you that 15w50 gives you oil pressures so astronomically high that it blows the oil sensor out of the back of the engine. So there is a limit on this. You won't find me using 0w20 and these engines and you won't find me using 15w50. Either. Zero base or 5 base and 30 or 40 for summer is where you want to be

 

I would add to @douglasjre's excellent advice that 'real oil pressure' is the way to go ... not a darn idiot light.

Another trick that I learned 'in the field' is filling to 3/4th level leads to a slight but measurable efficiency improvement in most ICE engines. This is not a trivial technique when refilling after an oil change and leads to a partially empty oil container.

My speculation is the slightly reduced oil level avoids any 'splash' interference with the crank and piston rods. It may also lead to a slightly higher and lower viscosity due to the lower oil pool mass.

GOOD LUCK!

Bob Wilson

 

When I put the spec'd 4.2 liters in our '10 after an oil drain and filter replacement, and leave the oil level check till after a drive or two, it's invariably about 1/4" below the top mark (equates to about a cup). I think it may be due to my DIY technique, raising the front quite high, versus a pro shop just raising the car on a lift (keeping it level). It also seems it'll be a slightly more complete oil change.

Anyways, it's fine by me, have that same hunch, that a slightly lower oil level means less splash.

 

Has anyone ever heard of a rock going in the drain plug hole and knocking the oil filter housing off causing oil to leak out ( three days after having an oil change) eventually blowing the head gasket?

 

No. Unless someone put it there. The rest is impossible.

 

the Toyota dealership service team claims that is what happened to my prius. I took it in for oil change, next day noise started, took it back they said needed new spark plugs, so they put them in, then next day while driving down the freeway a big cloud of smoke and a message on the dash telling me to pull over immediately. Had to tow it home then back to Toyota for them to charge me to put oil and filter on just to tell me the head gasket was blown and the coolant pipes damaged. All fluids were out. There is so much wrong here I don't even know where to start. But Toyota will not take any responsibility for the damage. Told me to turn it into my insurance.