5w-30 or 10w-30 in Southern California?

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Dec 21, 2003
What do you guys recommend. I have a 2001 Pathfinder with 48K on the vq35de engine and a 2003 tacoma with 16K on the 5vz-fe. The recommended viscocity for both is 5w-30 but both manuals say that you can use 10w-30 if temps are above freezing. I use 5w-30 synthetic oil in both. What are the advantages or disadvantages to 10w-30?
10W-30 will probably give you 30 wt. viscosity for more miles. This depends on the quality of the oil to start with, of course. Not all synthetic oils are top quality. My preference is to always use the highest viscosity oil allowed by your owner's manual for the climate.

I think 5w-30 is fine if you're using a synthetic. I'd be leary of running 5w-30 dino oil in such a warm climate though, I'd say 10w-30 for dino. You're already running syn, so I'd say stay with it. 10w-30 syn would hold up better if you keep it in for a longer period.
i also have a tacoma w/the 5vz-fe 3.4 v6,and live in socal.i just did my first oil change.i put 10w30 dino in it.[a coworker has an 01 w/ 20k miles on it using 10w30 dino,no problems]however, i am considering going to 5w30 synthetic next oci,hoping to get better economy w/gas prices and all.i want to see how it does on the dino first and let in run in a bit.
Douglas, don't fail to consider that the manufacturer's oil-viscosity recommendations in the US are substantially influenced by fuel-economy factors, AKA the feds' CAFE calculations and requirements. The difference in economy between a SAE hot-30 and -40 may be only a tenth of an MPG, but it all adds up for these manufacturers. Many manufacturers recommend lots thicker oils in other countries for THE SAME engine. (The next time I see that thread--about Toyotas--I'll bookmark it.)

In climates that virtually never see temps as low as freezing, I'd be using at least a 5W-40, and in the summer, I'd use probably a 10W-40.

I'm using Porsche's recommended M1 0W-40 in my Cayenne Turbo now, but I'll soon be doing exactly what I recommend above for you--5W-40 in the 'winter' and 10W-40 in the summer. I'll be changing about every 10,000 miles, HALF of Porsche's recommendation, so this will be easy for me.

I'm going with Red Line, BTW.
Peronely I would not use either. I would use a good 5W40 if useing synthetic. If running dino a good 15W40 would be my next choice. With that said given the choices you presented I would run 10W30.

P.S. I ran synthetic 5W40 all winter long down to -18F with no problems. In you climate you could easily run 10W30 year round!
I'm with both the JB's. 5W40 from vendor of your choice. It's interesting that nearly all syn oil here is 5W40 except Mobil 1 0W40 but they have Delvac 1 5W40 to cover that. Appears the US is following the 5W40 route too now with more appearing all the time.
As long as your owners manual states 10w/30 above the freezing point, I'd run the heavier weight.
I run the highest allowed weight for ambient temps to be encountered during that OCI and have encountered no oil related difficulties for the last 24 yrs.
Which particular syn are you running?? With a Syn in your climate, I think 0W, 5W, or 10W is fine. It's the viscosity of the 30 wt. that is most relevant. Cold cranking is not relevant for you.
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