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You should delete it because the post doesn't state that its out of date, a random lurker looking for info on here may just use it as a guide and follow it.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

 

Good to know. I just switched over to Valvoline Euro spec 5w-40 after running Pennzoil 5w-30 (both around $5/qt at Walmart) for the last 5 years.

My 2nd gen has to be in the 180k-200k+ range (have not had a dashboard w/speedo, odo, fuel gauge, etc. in 10+ years) and I drive it about 90 mi/day 5-6 days per week, 85% highway, 15% town, at 80-100+mph the majority of its highway time and 40-50mph while in town. It has been consuming oil for years at this point, but I have grown accustomed to giving it a drink at every fill up.

I live in FL now and it stays relatively warm/hot here year round. Hoping this might curb a tiny bit of its consumption, or if nothing else keep it rolling that much longer.

I think right now it consumes around 1/8th of a qt per commute, but that was on the 5w-30. Seems to be a bit better right after an oil change, and also when I keep the revs a little more tame. Some mornings I keep the pedal on the floor and let it rip. Other mornings I ride the power band at the sweet spot between 84-92mph.

By my calculations and dates scribed on each oil filter, I estimate I change the oil around every 7-8k mi. Should probably lean closer to 5k changes, but finding the right day can can be hard sometimes and before I know it, another 3-4 weeks have slipped past me.

 

You just convinced me to always do 5k mi oci's on all vehicles I own

 

I've got 20w50 Castrol GTX blend in my 2010 with 205k miles on it. About to switch down the 5w30 blend for the winter. Just some other oil I bought a while ago, when I was burning lots of oil. I've had 10w40 Castrol GTX blend down to 16F iirc. But was very worried about that. You will get some mpg loss with thicker oil. Between both Castrols, I've got about 8k miles. Was 50F the other week and the engine notably sounded different on cold start.

I'm down in Texas and I tow my boat sometimes with mine. Also oversized AT tires. 5k miles OCI. Did a B12 piston soak, so far I think its great but might be gaining oil? Never milky or anything.

 

Do you have oil consumption numbers for after the piston soak?
A friend raves about the improvement he got on his old Prii doing that procedure. He says he likes to let it soak for a week or so...

 

My biggest regret with my car is not doing one sooner. I did an overnight soak (about 14 hours) with one bottle of B12, turning the crank and topping off pretty often (while I was awake). I was burning 1qt every 1k miles. Now, I have yet to burn a 1/2qt in 7k miles and over the last 1500 miles (since my last oil change) it appears as if I've burned nothing at all.

 

Sorry to bring this thread back to life. I just found it in the list....

Technically I think you can leave all the pistons in line, 90°. And maybe jack the car in such a way to have the pistons level.
The idea is, the product dissolves the crud on the ring lands and oil control rings as it soaks past them on the way to the sump. Were the piston tops showing after the 14 hrs?

I'm glad to hear that only 14 hours of the soak did the job with that product!
I assume you immediately did the oil change so most of the B12 was out of the engine. I'd be tempted to do an early oil change after that.

 

I have to believe that rotating the crank helped. Some pistons would hold fluid better than others. I could always see the piston tops, but again some were better than others. I could see chunks of loose carbon after I was done, which actually made me a bit nervous. I ran the engine in maintenance mode for a few seconds with no plugs and coils to try to get the chunks and remaining fluid out and it worked great, they seemed really clean and dry afterwards. I was expecting a rough first start with lots of smoke, but there was NONE, it was a completely normal start. I did change the oil immediately and I also ran a bottle of Cataclean in the gas, but my next oil change was around 6k, so there could have been a small amount in there for that period.

As an update I just completed a 1700 mile road trip all highway and burned about an 1/8 of a quart (previous 2k miles since oil change was all city and burned basically none), it does seem like it's getting better over time. Most of the oil burning since the soak was in the first few thousand miles. I was as skeptical as everyone else, but now I would absolutely recommend it, which you'll probably see me do all over the forum. Still sad I didn't do this years ago.