For those of you who have the 3.5, what engine oil do you use? I'm wanting to go synthetic and am not sure about the best weight or brand. I'm leaning toward 5W30 mainly because it is a good all around oil. Thanks.

 

The factory specs. suggest using 5-30.
I use this in the winter and 10-30 in the summer.
I run the thicker oil in the summer because it's a bit hot (easily in the 100 degree F range) where I drive.
I use regular mineral oil, but usually change it according to the severe conditions schedule in the FSM.

 

10/30 castoroil edge

 

I am using synthetic, using factory weight 5-30. as far as brand, i get whatever is the cheapest at the time i go to walmart in terms of FULL synthetic.

 

I use Amsoil 5w-30 full synthetic. Started using at 5K. With their filter, they guarantee 25K or 1 year on oil and filter. I (wife) puts about 8K mileage a year, so we do the 1 year change. Have been using in all my cars for over 20 years w/o any issues.

www.amsoil.com

 

Nice, another Amsoil fan. I've used their 0w-30 for 3 years now in the Montero and love it.

 

For someone doing hard driving with the 2020+ Supra, what engine oil options are recommended?

 

I hope you realize that this "upgrade" from 5-30 to 10-30 makes absolutely no sense... the first number refers to oil viscosity at cold temperatures (-30°C/-22°F). Your viscosity at engine's operating temperature remains unchanged at 30.
I'd say stick to recommended 5-30 unless you drive your Monty at one of the poles.