tlwklw15

1999 Toyota Tacoma 5vz-fe

Acorn22

I just run some full synthetic Mobil 1 5w-30. No problems, and valvetrain looks very clean

Marc

5W-30 oil according to manual
any type you want

fierohink

I'm very happy with the semi-synthetic high mileage Valvoline and it's only $17 for a 5 qt jug.

https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1

75w90mantraN

Yr 2026: hey, what brand oil is best for the 3rd gen?

Avocado oil from Wal-Mart

plandy

Personally, when my SR5 was new I started out with synthetics. Then as they started getting more expensive I changed over to regular 5-20W by supplementing with anti-friction additives. I add upper lube additive to keep both sides running smooth. If you're not the original owner the engine oil should be flushed with "mild" certified for engine oil flush. But it may be detrimental for high mileage engines with lots of crud build up. Since I maintained my engine from day one the oil still looks new after several thousand miles from last oil change.

old87yota

What does "mild certified for engine oil flush" mean?

Personally, I would simply do regular oil changes with just a good, name brand engine oil, regardless if you choose to use conventional or synthetic.

No additives, no extras.

Today's oils are much better than when these engines came out and their additive packages built into the oil should be just fine on their own.

You can always shorten the oil change intervals if you feel the need.

Just my two cents.

plandy

A while back, I used a special kind of engine oil flush which was demonstrated to be very gentle on the engine seals. I forgot the name brand. Kept them in my trailer which was stolen along with everything inside. There are harsh engine flush products which can cause more damage than good.
I agree in most case all that's needed is regular interval maintenance. But for people who buy a used car with unknown maintenance record I'd do a one time flush.