I can't decide what type of oil to use for my 5.7L Tundra.

[Midcoast]

I know Synthetic is the best for any engine, and for the 5.7L engine. This is the easy part.

However, should I use 5w-20 Synthetic or 0w-20 (which only comes in Synthetic because only man can make it that thin)? I am from MN and so we have 4 seasons which includes cold temps as well as very hot temperatures. I also tow boats a few times per month during Spring, Summer, and Fall.

I was thinking about rotating oil but I am unsure if it would be bad for my 5.7L Toyota engine. What I meant is use 0w-20 in the Fall/Winter time and switch to 5w-20 Full Synthetic for the Spring and Summer time. What do you guys think on doing that?

If I was going to stick to just one oil all year, maybe 0W-20? But, will 0W-20 cause engine to run too hot in the summer time? Thoughts?

[NickBrewer]

IIRC, the manual recommends 0W-20 synthetic, but says you can use 5W-20 if 0W-20 is unavailable, or if you are operating the vehicle in high temperatures.

Ultimately, it is the 20 part of the viscosity rating that is important during operation. the 0 or 5 is the cold start viscosity, but either is actually pretty thin. I use 0W-20 particularly during the winter for the ease of cold starting and the fact that it will flow a bit quicker than the 5W-20.

Switching between 0W-20 and 5W-20 won't harm your engine in anyway. The only issue to be aware of is switching from dino oil to synthetic in a high mileage engine is not something I would recommend.

my .02

[M@D-M@X]

My opinion is that the low viscosity differences between 0 & 5 are very small, specially if you are using synthetic oil.

[INDYMAC]

Is anyone using a 30 grade engine oil? If so, how do you like it? Any UOA's so far compared to 5W-20 or 0W-20?

[RRzxter]

Is anyone using a 30 grade engine oil? If so, how do you like it?

Doesn't taste as good as the 20.
Seriously though, what would make you consider a 30wt oil when the engine requires a 20wt?

[Time4change]

Use a quality dino oil, change @ recommended intervals (ESPECIALLY during warranty period) and save lots of money.......

[INDYMAC]

Doesn't taste as good as the 20.
Seriously though, what would make you consider a 30wt oil when the engine requires a 20wt?

Doesn't the owner's manual suggest using a higher grade than 20 if operating at high speeds or towing?

[RRzxter]

Not sure. I'll have to look.

[ct03911]

I used 0W-20 in the winter and 5W-20 in the summer.
Mobil 1
I tow 7k loads in the summer.

[dickinsonj]

I run 0w-20 all year long without any problems in my 5.7, although when towing it could not hurt to switch to the 5w if you want extra insurance.

[Time4change]

I run 0w-20 all year long without any problems in my 5.7, although when towing it could not hurt to switch to the 5w if you want extra insurance.

0W or 5W have ZERO impact while towing.

[dickinsonj]

0W or 5W have ZERO impact while towing.

Good point and very true. When your engine is working hard both oils are 20 weight anyway, which is what the engine design calls for.

[RRzxter]

Is says you CAN use a higher weight/viscosity if you are running the truck under extreme conditions.
Doesn't say you have to or you should.
What I get from that is, unless you are doing a tractor pull or running the Baja 1000, it's probably not really necessary.
It also shows that both 5W-20 and 0W-20 will perform in temps from -20 to 100F.
And recommends 0W for the easiest cold starts and better fuel economy.
Like I've said in a few other threads, these aren't our grampa's trucks. Or the fuel and oils they were using either, for that matter.
I'm content with using the 0W-20, which is what the engineers said to use in all but the most extreme conditions.

[Hippo]

To me this is a no-brainer. I just follow what the manufacturer recommends.

Other than that, the best way to figure out the performance level of your oil is to do an oil analysis rather than visually inspecting the color of the oil.

[Time4change]

Is says you CAN use a higher weight/viscosity if you are running the truck under extreme conditions.
Doesn't say you have to or you should.
What I get from that is, unless you are doing a tractor pull or running the Baja 1000, it's probably not really necessary.
It also shows that both 5W-20 and 0W-20 will perform in temps from -20 to 100F.
And recommends 0W for the easiest cold starts and better fuel economy.
Like I've said in a few other threads, these aren't our grampa's trucks. Or the fuel and oils they were using either, for that matter.
I'm content with using the 0W-20, which is what the engineers said to use in all but the most extreme conditions.

I've run 5w-20 semi-syn (Motorcraft) from the 1st oil change @ 3,000 miles and every 5K miles thereafter, and I believe I've subjected my truck to some fairly extreme heat/towing scenarios,

With that said, I'd imagine at near 100K miles the tolerances have loosened up enough to run a 5W-30..............will it help?? Can't hurt!!!