0w-20 Motor Oil

I changed the oil for the first time in my 2012 Honda Civic with 0w-20 (Honda and Toyota have switched all automobiles to this viscosity). When I changed it, I noticed it is thin as water! This worries me. I know it is the “recommended” viscosity. But is it really enough to protect my engine in the heat of the summer? I live down south. We have average days of 90+ degrees.
Thank You!

That’s what the manual says. Cars are made with better, more accurate equipment these days. 0W-20 is being used in high-end BMWs and Mercedes as well. It is thin, but is also designed to keep your engine well lubricated, and the engine is designed to use it.

My 2011 Sienna calls for 0W-20 oil. I bought this vehicle when they first came out of March of 2010. I’ve run it on the interstates in 90 degree heat and have started it in the winter when the temperature was -10 degrees. I have over 25,000 mies on the Sienna and I have never had to add any oil between changes. Keep in mind that Toyota requires synthetic oil.

Yep, my 2011 CRV has the same oil in it. 4000 miles and still clean. I am getting close to one year mark, so have to change it soon. I am going with 0-20, that is what the car calls for and I am not going to outsmart their engineers.

Follow the owner’s manual (“Severe Service” intervals if it makes you feel better) and get in the habit of checking and topping off the oil level every 500 miles or so and your car will live a long and happy life.

Another factor to consider is that Honda also uses the oil as a hydraulic fluid to operate the variiable valve timing system. It’s best to stick with the owner’s manual recommendation.

Very, very few cars go to the bone-yard because of engine failure…Today, it’s the failure of the automatic transmission that takes cars out of service…Just change that 0-20 oil when it needs changing (I would not go over 5-6K miles) and the engine will last as long as it needs to…

When did Toyota change to 0W-20 oil? And synthetic?

My 2009 RAV4 requires non-synthetic 5W-30 oil.

I’m with Same. The hydraulic fluid in my tractors by necessity were also the Manual trans fluid in one, Hydro transmission in another, rear differential, wet brake suspension fluid etc. It needs to maintain ability to flow at very low temps in all these systems. If the parts of the motor, like an automatic transmission are actuated hydraulically, it seems the logical thing to do.
I had an engineering friend who years ago would replace the manual transmission fluid in his truck with automatic transmission fluid. He swore it made his truck start and shift more easily in cold with no loss of lubrication. His truck was going strong at 175K miles, so I had no reason to doubt these low viscosity fluids did their intended jobs and more.

And, if Triedag can go 25K between oil changes :=), it must be working.


Respects to your friend, but it’s’ not a philosophy I’d advocate. Automatic tranny fluid is designed to readily flow through control valves and readily transmit force, like brake fluid. Manual tranny fluid, like differential fluid, is formulated to withstand high compression forces, like those found between the gear tooth surfaces. Different animals.

I have no doubt you freiend’s truck shifted more easily ib cold weather. But thats’ not necessarily a good thing in the tradeoff is too great. In his case it’d be imporoper gear lubrication.

I had an engineering friend who years ago would replace the manual transmission fluid in his truck with automatic transmission fluid.

My 84 GMC S-15 pickup with 5-speed manual…the OEM fluid for that tranny was Dexron-III

Really? I wouldn’t have thought.

CarTalk is really the cream of the crop.
For comparison, I was just looking in another forum where someone has a 2003 Corolla that burns 1qt oil per 2500 miles.
The OP plans to change the valve seals, and if that doesn’t help, a ring job.
Another poster recommended 20w-50 oil instead of the specified 5w-30.

Really? I wouldn’t have thought.

I was surprised too. But GM has been doing that for a while. And without any problems either. But I suspect the tranny has to be designed for it. I wouldn’t do it on just any tranny. Not sure if they do it any more.

I don’t recall Toyota “mandating” synthetic oil. However, if you use 0W20 it WILL BE SYNTHETIC, no matter what car you drive, since you cannnot formulate a good 0W20 from normal mineral oil.

And, if Triedag can go 25K between oil changes :=), it must be working.

dagosa–sorry for the confusion. I have changed the oil. I’ve followed the directive from Toyota and change the oil at 10,000 miles. I’ve changed it twice at this point. Much of my driving is highway driving. I talked this 10,000 mile interval over with the service manager (not a service writer) at the dealership, because it seemed like a lot of miles between changes to me. He said he would be glad to take my money, but the engineers believe that the synthetic oil along with the design of the engine makes more frequent changes unncessary. For an old timer like me who remembers when it was recommended that oil be changed every 1000 miles back in the late 1940s and early 1950s, this seems like a lot of miles between changes. However, my 1965 Rambler required oil and filter changes every 4000 miles, so I guess oils and engines should have improved after 47 years.

As far as the recommended 0W-20 viscosity is concerned, I have no problem with that. The late Tom McCahill back in the early 1960s said that he always used oil of higher viscosity than the recommendation. If the factory recommended 20 weight, he ran 30 weight, gave a little time for warmup and claimed to never have had a car that used oil in 80,000 miles. I used the factory recommendations and had 150,000 miles on engines during the same time period and didn’t have a car that used oil, except for my 1971 Maverick that used oil until I replaced the valve stem seals. On the other hand, I had a friend that believed in putting a can of STP in the oil at each oil change and his engine was burning oil at 100,000 miles. STP did raise the viscosity of the oil.

I know of only one time when engine life was stretched using an oil of a higher viscosity. When I was in college, I was returning to campus with some friends in a 1950 Pontiac. About 20 miles from campus, a connecting rod started knocking loudly. We pulled into an all-night service station and replaced the engine oil with 90 weight gear lube. We made it back to campus. The next day, a wrecker hauled my friend’s 1950 Pontiac to the scrap yard.