5w-30: Have I been using the wrong oil?

For years and years I have been using Mobil 1, 5w-30, full synthetic motor oil in my 2010 Tundra which currently has 178,000 trouble free miles on it.

I happened to be looking at my owners manual recently and I just about passed out when I saw that the manual recommends either 0w-20 or 5w-20 oil.

I was shocked to learn I've been using the wrong stuff.

Then I started thinking. Seeing how I live in Phoenix, it's hot here, maybe I read somewhere that 5w-30 is better in the extreme hot temperatures we have in this part of the country.

I this true?

Should I go back to one of the recommended grades of oil?

Thanks.

 

I run what the manual says, but I doubt there's any effective differences running what you normally do. I wouldn't worry about it. If you want to start running what the manual says that's your call, I don't think it makes a difference either way.

 

5W30 is ok to use. I've been using it in my 2012 Tundra since purchased in 2014. 5W30 is used in the same engine in other countries.

 

I was going to use 5w30 but using 0w30 now. I don't think either one will give us a trouble.

 

You should be fine but the weight is stamped on the fill cap.

 

Yep

 

You just lost a tad more mpgs than the rest of us. Nothing to worry about.

 

+1. The 0w-20 is all about efficiency, less friction on the motor for better fuel economy. I think this thinking came from Cali for emissions control, but I believe that other high emissions states have adapted this also, thus the recommendation in the owners manual for 0w-20. The only thing that I can think of is the 5w-30 could possibly wear the engine out pre maturely. But then again maybe no adverse effect at all. The book does say that if 0w-20 is not available to use 5w-30 but dump it as soon as the 0w-20 is available.

 

I did a little research on the issue and found that the reason for the light weight oil is for emissions. If the engine has less friction it will take less power to do the same job, thus better fuel economy. You can use what ever you want, but to keep within emissions regulations the 0w-20 is the right oil. These engines are tough, but for longevity I would stick to what the manufacture recommends. Yes some other countries use 5w-30 but they may not have the stricter standards for emissions that the US has, and some with the same or stricter standards like the US, would require the thinner oil. The manufacture suggests this to meet all emissions requirements for any country that the Tundra is sold in. Less friction in the engine is always better for longevity in my opinion.

 

Have you got documented proof to back this claim up??

I find the statement very questionable and don't agree with it, fake news.

 

You must have missed the memo. Some in todays society choose truth over fact

 

I was thinking the same thing. The OP has 178k on the truck and i doubt the engine is prematurely worn down from the 5w-30.

 

For some reason the manual is what made him almost pass out. Not the stamping on the fill cap every time
He did an oil change.

 

Did a whole thing on this exact topic on Bob is the Oil Guy...THE motor oil geek forum. My high milage 2010 5.7 was noisey on cold starts with 0w-20 and 5w-20, so I switched to Penzoil Platinum Synthetic 5w30, ran great for a few years, then to Mobil 1 High Mileage synthetic 5w30, and that was even more quiet on the 10-20 degree days. Best I could determine was 0.6 average mpg less with the 5w30 over several years. As noted above, the Toyota 5.7 uses synthetic 5w-30 in other vehicle platforms and countries. Much ado about nothing.

 

20w is “recommended” for a marginally better MPG rating...where 30w is flat out a better oil. You do you.

 

The mpg difference between 20w and 30w is miniscule. Ive tried both, can’t find a difference at all.

OP lives in AZ, so that 30w has probably done years of benefit for his engine. It’s hard to find, but if you find an Australian copy of the 5.7 manual, it recommends 5w-30.

i run 5w-30 for the hotter half of the year, 0-20 in winter because no store around me sells 0-30

 

Can you post a link? I’d like to read it.