Thats why I use synthetic, I have seen the wonders of it. Chevy ball joints that last 150K, when chevy says they are good for 70K, same with 700R4's, dad had one in his 84 burb that went out at 140K, twice the standard.. and that was after he put the banks turbo on his 6.2L... had synthetic in it... He has also been running synthitic in his big rig diesels in his commercial fishing boat and everything has MUCH better wear than it should... Like I said they have been around a long time, AMSOIL was the first, in 1972 it became the first synthetic motor oil in the world to meet American Petroleum Institute service requirements... I trust it because it works... that and it saves $$$...

 

There really is no debate. Synthetic oil not only lubricates better but also protects better. No speculation just fact. Heavy equipment is a different story. If you change your oil regularly dino oil is fine. If you drive freeway miles mostly, dino oil is fine. Take it for what it's worth, piece of mind. It is a better oil though.

 

The thing with diesels is you really need a bypass filter to get the maximun out of synthetic. The soot builds up in the oil and a normal full flow, a really good one, filters at 15 microns. A good bypass filters soot down to 1 micron, wear stops at 5 microns... so better oil and better filtration = LONG oil life...

 

I've always ran 15w40 delo in my yotas. never had a problem and ran one of em up to 390k.

 

wat would u recommend for a 97 tacoma with 2.7 n 156k miles

 

I'm going to take a stab here, and we'll see if anybody agrees with me: 10W-30

 

Use the lightest oil you can without it burning a ˟˟˟˟˟load of it. Heavy oil (20w-50, for example) protects the lower end better under harsh loads/heat, but it tends to wear cams more because it doesn't flow to the upper end as well. Like was said before, synthetic is the best protection you can get. I'm running Mobil 1 for 10,000 miles with a filter change every 5k. This was confirmed by an oil analysis from Blackstone Labs. (www.blackstonelabs.com)

 

IIRC 5w-30 is whats in the manul, only go to 10w-30 if your burning a crapload of oil...

 

A couple of more reasons for synthetic; it has a higher flashpoint and doesn't sludge...especially in newer motors.

 

Right. But 156,000 miles is a lot of miles. There must be some wear on the engine. The gaps that were thin when it was new are wider now. That's why I thought it might be wise to move to 10W-30. I think the goal might be to prevent getting to the point where you're burning a crap load of oil. Or at least put it off as long as possible...

 

I started synthetic 5w-30 on my 92 with 150K..... no issues.... Unless the engine has been abused I think it will be fine with the OEM reccomendation.

 

Okay. I had a '95 pickup, with the 3.0, and I just used 10W-30 in it. I worked that engine pretty hard, hauling a trailer and pushing snow. I didn't have any major issues with it, but I did notice that it consumed more oil as the years went by. At 150,000 miles I was adding about a quart every three fill ups or so, whereas, when it was new, it wasn't consuming nearly that much. Maybe half as much.

So... let's say you have a new engine. Let's say it takes 5 or 6 fill ups before you have to add a quart. You're using 5W-30, per the manual.

150,000 miles later, you're adding a quart every three fill ups. It's therefore consuming twice the oil as when it was new. So, assuming we aren't dripping oil from a bad gasket somewhere, I think we can we conclude that the gaps where the pistons slide are loosening up or widening, can't we? And, therefore, do we think it's wise to consider switching to a thicker-at-startup oil, such as 10W-30?

What do you think?

 

I have never owned a vehicle that has used oil since new (doesnt sound normal at all)... Even on my 92 with 160K I only add a quart every 5K miles, at most... so I cant go there... Even the 3.0 I owned with 200K didnt burn a quart every 3 fillups... so I guess its based on each engine... My 95 4runner with a 22RE never burned any oil and I sold it with 15x,xxx.. 5w-30 in everything (mostly synthetic too)... And when your running hard they are both 30w... so I still think 5w-30 unless it burns a bunch of oil on startup.. then switch thicker... but you want burn any more/less with a 5w vs 10w when you talking cruising amounts... but like we have shown each engine is different... Your oil pump is also older so the heavier oil may not flow as quick on startup.. so again, unless you have a bad oil burning problem at startup I would run 5w-30... the oil pump will like it better... and as long as you dont fire it up and race it across town, i.e. let it warm up before laying the power on.. I think the 5w is better, flows quicker and at idle you dont need the massive pressure you do when driving.. so a light coating of 5w is better than a lighter coating of 10w.... so thats my .02

 

Okay, that sounds logical. At first I didn't think your answer a few posts back was correct, I didn't think you thought it through. But now I see you are probably right. Good answer. Thanks

I babied my '95 truck in the beginning. You're probably right, mine probably didn't burn any oil when it was new either. But I do run mine hard. And I do a lot of starting and short trips during the day, like 10 or 15. And unfortunately, every morning when I start out, I have to climb this hill for the first quarter mile or so. I'm sure that doesn't help. I also got lazy on the oil changes towards the end. But I always check the oil level every fill up. I could have got a lot more miles out of it, if it wasn't for the rust that had corroded into just about everything nook and cranny on the truck. Thanks again.

 

To add to the mix.....

http://www.carbibles.com/viscosity.html
http://engineoil.blogspot.com/

 

Interesting info on the 0w... didnt know it was a 5w that poured colder, now I dont feel so weird running it when OEM is 5w ... Good thing as Amsoil's best gas oil is a 5w-30.

 

I thought that Syns were only good for newer engines. Engines with more than 80,000 miles might not do good with syns because it cleans the motor up and could lead to a spun bearing. And especially motors with close to 200,000 miles. Is that a correct line of thinking?

 

If you're talking synthetics, Amsoil being a solid brand, 5w30 and 10w30 are very very similar. Both are 30 weight oils at operating temperature so you're covered there. The only difference between the two Amsoil oils is the 10w30 will be slightly better at resisting burn off than the 5w30, but the 5w30 will be slightly thinner at start up. So you kinda gotta make trade offs. But considering both the 5w and 10w oils listed both have their pour points at -58, I think you'd be best sticking with 10w30 if you can, but I wouldn't hesitate to run 5w either if I had to for some reason. Now if I was running in very cold temperatures, like freezing temps and regularly, I'd probably considering going to a 0w30. But again only if it was consistently very cold. I have had no problems with my truck starting with Mobil 1 and Amsoil 10w30 weighs in freezing temps before.

 

nope.... NEVER heard the spun bearing thing.. thats odd... the common one is the synthietic will cause leaks.... also false. It will clean your engine up and possibly expose leaks that have been plugged.. .but on newer engines, even hi mileage ones, thats not an issue. I have switched rigs to syn at 150K w/out issue... and my dad has two rigs with almost 200K with syn and they run great, in theory due TO synthetic.

I prefer 5w-30, as it the OEM reccommendation for all of my yotas...

And there is also a HUGE variance in quality of synthetics... normally associated by price The amsoil TSO is almost 10/qt... and probably the best gas oil on the market... I havent seen a better one. Then you look at wear/scar tests and some of the cheap synthetics are worse than some dino oils

 

Absolutely right, here. There is never a bad time or engine to run on synthetic. The leak thing is urban legend, synthetic will not /cause/ leaks. Years ago there was some truth to it, because the seals need additives to synthetic oils to keep them swollen, which replaces naturally occurring compounds in dino oil. But, every synthetic made in the past couple of decades will have the right stuff. Like AH65ID said, it does tend to clean your engine of sludge and stuff, which might cause a bad seal to start leaking as the junk is cleaned out. The seal was bad before, just that the leak was probably clogged. The only reason not to run synthetic is if your engine leaks or burns significant oil already, it's more expensive to let synthetic dribble to the ground. But as long as the oil stays in the engine and isn't blown by the rings, any engines can run synthetic if you want.