acquired a 87 4runner 4 cylinder auto

[02runner4]

hello,
I recently bought a 87 4runner 4 cylinder auto. I changed oil to mobil 1 10w-30 but I want to know what you guys are using for your 1st gen runners.
The manual gives you lots of options for different grades. I picked 10w30 since it will get cold anytime in about a month here near Washington D.C..
I've never actually used 20w-50 or similar range but I want to know if it's good for my engine. Wouldn't it be too thick?
I changed out front and rear differential fluid to mobil1 75w-90. The transfer case calls for ATF, not gear oil. I thought it was kind of strange. How should I go by changing the transfer case fluid?

 

[94Beast4Runner]

Go with what the book calls for.

mobil 1 Non synthetic?

Thicker is better if you have small oil leaks and dont wanna fix them anytime soon. but thin is good for cold temps cause your engine can move it around better. pretty much your call though. i have read many a articles about oil, what brand or grade to use. User discretion, what ever works.

 

[02runner4]

mobil1 synthetic for both engine and gear oil.
There is no leak on the engine or anywhere. I just want the best protection regardless of MPG.

 

[94Beast4Runner]

My engine rebuilder told me not to use synthetic on older engines cause it can cause leaks cause it is so thin. Standard oil will give good protection. Depending on brand.

 

[02runner4]

My engine rebuilder told me not to use synthetic on older engines cause it can cause leaks cause it is so thin. Standard oil will give good protection. Depending on brand.

What brand and grade of engine oil do you recommend?
I hope I'm ok using synthetic gear oil in differentials.

 

[94Beast4Runner]

the diffs and trans case are fine to use synthetic. synthetic should be the only thing you put in them.

Just the engine oil is the only one you should be careful changing to synthetic.

I'm not to sure what the climate is like in your area. I usually only use castrol oils.

 

[moparvwfreak]

My engine rebuilder told me not to use synthetic on older engines cause it can cause leaks cause it is so thin. Standard oil will give good protection. Depending on brand.

250K in my jeep and i run synthetic. have for the last 100k. it actually slowed my oil leaks. jeep 4.0l are notorious for massive rear main leaks. i just recently upped it, within the last 20K, to 15w50 mobil 1 full synth.

 

[SlowYourRoll]

22re automatic? how's that treating you?