Of course you are probably right... only thing that might happen in some cases is, if the rings are worn, you might reduce blow-bye and increase compression a bit. Dunno.

 

You're welcome. Hope it works out for you.

 

Well after reading this thread I'm still a bit unsure what Im going to do with my oil.
I have kind of a weird thing going on with my 3vz. I do a fair amount of driving on the interstate (3K @65mph) I've noticed this summer that after about 30-40 miles the oil pressure gauge goes from dead middle down around the 1st tick mark, no change in RPM....it just goes down.

My guess was ok i'm running 10-30 switch to 10-40 there has to be some sort of oil break down going on. Now all that really did is (while the engine is cooler) bring the needle slightly past dead center on the gauge, but it still drops to slightly above the 1st tick mark after 30-40mi, only slight improvement.

I was considering switching to a 5-50, but now with all the talk of possible damage to the top end not getting enough lubrication I'm hesitant. I'm planningon taking the 4runner(95) to Taos NM this weekend and I'd like to see some decent pressure on the gauge, then again as long as it's above the 1st tick that could be in spec.

What would you guys think? Long trip=5-50 or just leave the 10-40?

 

a synthetic oil will burn faster because of the molecular makeup of the molecules, in a syn they are in long chains and even a 20-50 will flow better than a 15-40 conventional oil, if you leak you will leak more with a synthetic, same with consuming it, my opinion is to run 15-40 rotella, its what i have been using for the last 3 years in my runner with over 200,000 miles engine is fine, you get better protection with a diesel oil, after us switched to ulsd additives were added to the oil to keep it clean and top end lubricated.

 

Stick with 10W-40. It's normal for the pressure to drop as the oil gets hot.

 

Thanks, yeah I would go with synthetic my 4runner just turned the 1/4 million mark and it has a rear main leak, it doesn't leak a lot but I still wouldn't chance it. I've read about people using the diesel oil, but I've never tried it so I guess it will be a good experiment. Thanks for your reply.

 

not ganna read through the whole thread but obviously everyone with a keyboard is an expert on motor oil, all I'm going to say is higher mileage motors benefit from thicker oil and unlike most of the people on here I actually have a close affiliation with the top brand of motor oil which I will not name in this post

 

Mobil 1 High mileage, it has seal protection in it

 

Cool, thanks I think I might try and and find some Mobile 1 high mileage 10-40. There are really a lot of opinions on oil types. Thanks for the replies.