5W-20 versus 5W-30 Motor Oil.

The lower number in the oil spec states how low in temp the oil will maintain a certain viscosity. The higher number indicates how high in temp it will maintain a certain viscosity. In colder weather, use an oil that has a lower low number and a lower high number. I higher temps (like here in the Houston TX area) you want to use an oil that has a higher low and higher high number. I have been putting 20W-50 Castrol High Mileage in my over 10 yrs. old Altimas - it also helps with the sealing and keeping compression up. Now, I don't know if this same rating goes with the fully synthetic oils or not - maybe someone with more info can chime in.

 

Ya. My 4 cylinder, 2007 manual says 0W-20 or 5W-20. I live in, and bought it in central Iowa.
I heard the 2005 model 4 cyls used 5W-30 but can't confirm that.

 

So the fact that I just accidentally mixed about 3 qts of 20W 50 in with the normal 5W 30 means I'll be ok 'til my next scheduled oil change?

Most of my driving is around 60 mph keeping the tach needle under 2K...

I'm in GA.

 

I believe the VVTI system is controlled by oil pressure. I would run what Toyota says to use. In this case 5W20 or 0W20 for the newer 2.7. Having said that, there is not much difference between 5W20 and 5W30, so I would just wait until the next oil change and put in the correct oil. JMO.

 

well, since the dude changed his oil back in 2007, I'd hope he figured it out by now.

 

Whoa! I didn't even notice how old this thread is. I'm gonna go outside and kick my own ass.

 

20W 50 was put in by mistake. I had it for my '72 landcruiser but...

It's warm weather down here so I'm not gonna sweat it. I'll just sweat.

 

FWIW - The toyota manual O-K's higher viscosity if you will be working the engine harder, or if the temperature is extreme. So it is acceptable, as per Toyota

 

Oil flow is just as important to lubrication as oil viscosity. If you run too thick of an oil, you may not be helping your engine, especially at start up where most engine wear occurs. Here's a link to an article that someone else posted on TW that explains oil viscosity really well.

http://ferrarichat.com/forum/faq.php?faq=haas_articles#faq_motor_oil_basics

 

For the 1st 25k or so miles I've been running 5w20 Synthetic but recently switched over to Mobil 1 0W-30 Advanced Fuel Economy (green cap) in the 5 qt jugs sold at WalMart....I have noticed a slight increase in mpg (1-1.5 mpg on avg per tank)

Currently Mobil 1 is offering a $10 rebate on their AFE oil in 0w20 and 0w30 which brings cost down to $12 for 5 qts...$2.40/qt
I live in NH so it does get quite cold in the winter

 

I'm an running the same oil; as my truck sees a lot of full throttle, towing, and so on. And the 0W part will mean easier starts come winter. Best protection all around, and the manual Okay's it!

 

Thats correct. My 05 says 5-30 on the cap.

 

AMSOIL 0W-30

 

The 5W-30, and 5W-20 is the same thickeness or thin, the number ""5" is the thickness of the oil, the "W" means its for winter and the "20" is the viscosity.
The Toyota Engineers design and test their engines for a certain viscosity, and with current and future EPA laws they want an oil that gives the best gas mileage.
You can put any rating of any oil you want in ur engine and it won't harm it, you can use a 20W50 if you want, but I wouldn't recommend it, I would recommend to stick to what Toyota says to use.

 

Some of you might think I'm nuts but I ran 5W40 in my last 05 year round in New Hampshire for the last 95k miles I owned the truck. And for the last 125k in my wife's 00 4Runner. It's in my "new" 05 now. CAN YOU BELIEVE IT!! Toyota spec'd 5W30 for both and I changed to something else!! And nothing happened! Holy Cow!

Seriously though everyone has their opinion on what's the "best oil" and the best viscosity. Run something close to what Toyota suggests and keep using the same brand, use good filters, and forget about what anyone else says.

 

for the win....the epic mfw!!!

 

Just use what is in your manual. The smartest engineers that designed your engine have TOLD you what to use. So use it. If it says, 5W-20, use 5W-20.... if it says 5W-30, use 5W-30... if it says 99W-turbo150.... you get the picture. Just drain the purple and put it back in it's own container and use it as a top up for your other vehicle; there's nothing wrong with it, 99% clean, just tiny bit of residue from the older oil - no big deal.