Is 5w-30 recommended in hotter climates?

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Dec 5, 2002
I live in the South where the winter is not really that cold but summers are brutally hot.

My 2001 Tacoma manual calls for 5w-30 and I've been using Mobile 1 in this weight. But I've always felt this may be too thin.

Nobody seem to make a 5w-40 synthetic and I don't want to use dino oil. Am I overly concerned about the oil getting too thin?

You most likely will find that viscosity doesn't make a difference in wear whether your in a cold climate or warm. Anything from a 20wt to a 40wt is fine in any gas engine. Certain viscosities might give you better wear depending on the engine, but that would have to be determined through testing. Generally speaking the additive package and quality of the lubricant are what make a good oil.
There are pleny of 5w40 synths to choose from. But, sometimes its difficult to find them.
Since your're south, why not use the 10w30 or 40s.

Mobil1 makes a 0w40 and Delvac1 5w40. Redline has a 5w40. Castrol/QS/Silkolene/Lubromoly/Maxima/synogen/... have 5w40 and GC is a 0w30 worth trying.
Toss in all the 10w40s out there and there are plenty of choices.

Or, use 1 quart of 15w50 with the rest 5w30.

Mobil1 makes a 0w40 and Delvac1 5w40. Redline has a 5w40. Castrol/QS/Silkolene/Lubromoly/Maxima/synogen/... have 5w40 and GC is a 0w30 worth trying.
Toss in all the 10w40s out there and there are plenty of choices.

Or, use 1 quart of 15w50 with the rest 5w30.

Definitely lots of choices. Any of the above are excellent. Delvac 1 is highly regarded if you can find it.

[ October 26, 2003, 07:10 PM: Message edited by: buster ]
Not to leave out Chevron Delo, Shell Rotella, and other group III 5W40s that cost half as much as Delvac, and work just as well. All API CI-4s and SL.
Why pay more just because a product is made from a PAO base oil??
Like Buster said, its the additives that count in a quality product.

[ October 26, 2003, 07:32 PM: Message edited by: userfriendly ]
Doesn't your owner's manual also allow 10W-30 to be used except in the coldest weather?

For a point of interest, find the four or five letter & number code for your engine, 22RE or 1MZ-FE or whatever, and look at BP's engine oil guide for Australia or U.K. It'll be a different vehicle but the same engine

You'll probably find an oil recommended that seems to be totally weird...15W-50 or 20W-50 or something that doesn't seem right at all--but it's the same engine in a different country! You'll find the same thing in the Valvoline guide or any other brand or country you can find.

Toyota allows 10W-30 any time the temperature is above 0F. If you feel that viscosity M1 is too thin you might also try adding some Schaeffers #132 to it. I'm trying that now in my 3.4L Toyota engine and I'm looking forward to seeing how the next UOA compares to the previous one without the #132...

[ October 26, 2003, 07:59 PM: Message edited by: jsharp ]
Thanks for the tip Ken.

I went to the BP website and for my engine (listed in a Landcruiser, but same engine) they said:

Visco 3000 or
Visco 5000.

I did a web search and found that:
Visco 3000 ==> 15W-50
Visco 5000 ==> 5W-40.

Therefore it seems that 5W-30 may be a tad light. I'll use the suggestion of adding 1 qt of 15W-50 at my next oil change to the 4 qts of 5W-30 that I already bought.

Thanks for all the help. What a great forum.

I run Amsoil ATM 10w-30 in my 94 altima and ASL 5w-30 in the 2k Maxima in Hotlanta.

I would recommend the Amsoil since it is on the thicker side of 30 weight and from an MPG standpoint better than a 40 weight.

Both oils are very shear stable with no consumption issues.
par I just purchased a 20 litre drum Visco 5000 5W40 a low 40W (13.95 cSt @ 100C) after Timken testing gave excellent results. I was led to believe you can't get BP oils in NA, is that incorect?

I believe you are correct. I haven't seen BP oils in the 'normal' stores here, but that is not the same as assuming they are unavailable. As the above posts suggest, however, we have many other choices.
Hey Par, Big Lots has Havoline Syn 5w-40 for 1.99
The best deal in the country right now as far as I'm concerned
Another coice. Use 10W-30 Mobil 1 with maybe a quart of 15W-50 Mobil 1. That gets you into a thicker 30 wt. I have done it for years and I believe some others on here have done it as well. The oils are totally compatable and even Mobil says you can mix. (Although they can't recommend it)
Yes in the everywhere else in the world...

Viscosity choice should be exclusively decided on prevalent exterior ambient if you're in FL, there probably should be no reason to need a 5W, let alone a 0W.
Dr T;
True, but most people it seems would rather use a light weight oil with a bunch of VI improvers in a hot climate than a shear stable single grade SAE 30 or 40 that has better lubricating properties.
As soon as someone mentions mono-grades the pack mentality becomes evident.
Perhaps there just isn't enough single grade oil to go around if everyone switched from their multi-grades to seasonally adjusted mono-grade viscosities, which are the industrial workhorses.

I'm quite sure that multi-grade engine oils are cheaper to produce than single grades.
Multi-grade engine oils, even the "synthetic" ones
are like wienners and spam....
If you knew really what they were made from, you probably wouldn't eat them.

[ October 27, 2003, 08:03 PM: Message edited by: userfriendly ]

When straight 30wt diesel oils were replaced by 15w-40 multigrades, there was a significant increase in engine life and a significant decrease in oil consumption. It was also possible to actually start these engines in cold weather, without resorting to starting aids.

You might as well campaign to bring back bias ply tires, drum brakes, points/condensers and solid axles ...
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