Advice with viscosity chart for older vehicle.

[OceanRuns]

I have several older Japanese vehicles. Oil information, like what's posted below, is similar in a few different owners manuals. This particular manual is from a 1983 Toyota Tercel wagon (3AC engine.)

On the back of the manual, it says to use 10w30 or 10w-40 in 'normal' temperatures.

However, on the viscosity chart inside, it seems to indicate that if you're driving in temperature that is ever in the 70s or 80s, you need a 50 weight? Wouldn't most people consider those temperatures in the 'normal' range?

I'd like to protect the engine. I currently have Delo 10w30 in there (partly for the 1200ppm level of ZDDP). Sometimes on the coldest winter day it is 30 degrees. Sometimes I go somewhere in the summer and it's 90s. Most days are 40s or 50s in morning to 70s afternoon.

Looking at this chart, does it seem like 50w is necessary of you're ever driving in 70, 80, or the occasional 90 degree weather? Or, is this chart a bit of a relic?

Thanks

 

[Cardenio327]

It looks to me that the chart is trying to say that 10w30, 10w-40 and 10w-50 are fine for any temperature above -10 °F, so 10w30 will be fine no matter how hot the weather gets.

 

[Bandito440]

Originally Posted By: Cardenio327
It looks to me that the chart is trying to say that 10w30, 10w-40 and 10w-50 are fine for any temperature above -10 °F, so 10w30 will be fine no matter how hot the weather gets.

Yep. You're fine with 10w30. Maybe 10w-40 if you're beating on it.

 

[BitterShard]

Do: "Use SAE 10w30 or 10W-40 if normal temperatures are above -10F"

Don't: Use 20W-x below 10F, or 5w30 above 50F

 

[Boss302fan]

I would use 5W40 Rotella.

 

[Dyusik]

I would use 10w40 or higher just to get out of the cafe restrictions that affect the 30wts. Zinc follows phosphorus and you don't want phos limitations of current era oils.

 

[tomcat27]

10w-30

 

[OneEyeJack]

Keep doing exactly what you're doing. Don't fix something that is working just fine.

 

[aquariuscsm]

Use a 10W40 in your favorite brand year round.

 

[bigt61]

10W-30 or 10W-40 dino or blend. Use a HM oil if it needs it.

 

[OceanRuns]

Appreciate all the responses, thank you. Seems I may be looking at the chart incorrectly.

What are your thoughts on a Delo 400 15w40? Relatively inexpensive and has 1300 ppm zinc.

Which 10w-40s have decent zinc?

 

[OceanRuns]

How about this chart from a 1978 Toyota Corolla. (2TC engine)

It's another 4 cylinder engine from basically the same era (5 years earlier). They default to 20w-50 (20w-40) on the back cover. And then the chart seems more definite.

Thoughts on which oil to run? Was the 20w-50 basically just the main oil then that everyone used, or do you think a 2TC really needs thick stuff? Modern 10w30 too thin for this?

 

[Dyusik]

I like delo. I would use it in just about every thing short of gdi in a warm (20deg and up) climate.

 

[Bandito440]

I'd use the same in the Corolla, and all from that era. If you're okay with synthetic, Mobil 1 10w-40 High Mileage would be great for annual oil changes. It has higher levels of additives too.

 

[Nickdfresh]

Mobil 1 HM 10W-40 is great, but any HM 10W-40 would do...

 

[slacktide_bitog]

I'd use T6, M1 or Edge 0w40, or Edge 0w30 (which is a thick 30)

 

[Merkava_4]

Get you some Chevron 10W-40 at Costco.

 

[Garak]

There is no reason whatsoever to switch away from the 10w30 Delo you're using right now. It's a better choice than just about any 10w-40 I can think of, although the bar isn't set very high when it comes to 10w-40.

 

[Shannow]

Spot on Garak.

 

[OceanRuns]

Really appreciate all the responses.

Anyone know of a 10w-40 conventional with boosted ZDDP?