It little tired engine have 150,000 miles it plow truck. 93 Bronco it not my bronco it friend's bronco.

He use 10w30 but he is worry about oil lose viscosity when it get hot while vary rev during plow. It get hot oil pressure idle at 10 for 2 1/2 hour of plow. Without plow it get 16 psi.

He is think use 5w40 Shell rotailla T synthetic. It ok to use in that engine? It will see from 800 to 3,500 rpm all times like you do in city stop and go. He would warm up engine for few mins so that be ok for 5w40 in 0oF

 

I woudn't worry about it. I have a 302 and I run 5W-40 RTS. I live in east Tennessee, so it doesn't get below 0F often, and more like 10-15F is a common low.

It's fine.

 

I would suggest 10W40, you need the extra protection of the 40 doing this kind of work with that small engine. Does he keep the engine block heater plugged in or garage it or plug it in the night before he's going to work it?

 

ya i agree with g_k50 10w40 is the way to go

 

that 5w stuff is meant for the newer motors with tighter tollerances. 10-30 or 10-40 will work fine for our vehicles

 

Wow, if I wasn't chilled out right now I'd go off in a cursing rage.

5W-40 is NOT thinner than 10W-40 or 15W-40 at operating temperature. It's the same. The first number does not affect the viscosity at 100C.

You guys should not be spreading false information without knowing what the numbers actually mean.

The 5W in 5W-40 is about cold flow. When warm, it will be just as thick as a 10W or 15W-40.

The answer is yes, your friend should use the 5W-40 over a 10W/15W-40 in the winter.

There is one other guy in these forums that I've noticed also has much knowledge about oil. Steveandmandy or something is his name. I really hope he chimes in.

 

chill out man, he's talking about going from 10-30 to 5-40 or 10-40, only one person implied (and barely) that the first number meant oil viscosity at temp.

just reread the thread..

 

Then why would anyone suggest 10W-40 over 5W-40? Especially in winter.

And, yeah, maybe I did jump the gun, but the guy at Autozone sticks in my head when I purchased some 5W-40 2 weeks ago. He said "What's that for, a VW or something?" I said "No, my truck." I didn't bother to tell him I was putting Rotella in my GAS engine. He said "You don't use that 15W-40 stuff?"

But, all I'm saying is, the lower the first number, the better. Even in summer when it doesn't matter as much, it's still better. Better start up flow is always better.

http://www.youtube.com/watch?v=_qRXG2mf9is

Should make anyone want to run a 5W-40 over any 40 weight. I know it's 15W-40 vs 5W-40, but still... just neat to watch.

 

when running the 5w stuff at startup i have heard far more lifter noise and piston slap then when running 10-30 or 10-40. that noise isnt good so why would using that be better?

 

It's probably in your head. Do you, and I'm not being a smart ***, but do you understand what the numbers mean on the oil bottle?

 

Yeap 10-30 or 10-40 . Instant oil press a start up , never had any problems .... Lew

 

I always run heavy in the winter, I feel like the lube sits better on the parts for the initial start up. It takes a while to get oil to flow in cold temps. In cold weather it feels good being able to reach into my valve cover and feel a nice thick coat of oil on my rocker arms.

i think that's why some people use heavier winter weights in the winter in big trucks (10-30/40 or even 15w), like with diesel. they're low reving, long stroke engines that need to flow oil over bigger areas with less pressure.. the thicker W number gives you more residual oil on your cold starts (sticks to stuff better instead of all draining into your pan). The biggest downside are the hard starts, which are especially hard in some of these older big V8s. just theorizing, im not sure how the actual physics would work out.

or you could simply say high torque, long stroke, low reving engine like a diesel.. diesel people use 15/40, so it makes sense to follow their lead.

you also have the old seals to deal with, that super high viscosity in the winter can mean a lot of burnt oil on a cold start in these old engines.

edit: cast iron, huge parts, old engine.. basically, i dont think 5w is enough protection on startup on these old, huge engines.

keep in mind that the viscosity can be anywhere between 5-40 in 5w40, even in the summer. the later number is hot temp, it's not going to be 40weight on a cold start if it's 80f outside. 10-40 means an overall thicker oil.
it's more of a range of thickness. In 10w40 for example, the 10 is for -35C, which is lower than any of us will operate our cars at, i think the later number is for 100C, which is the operating temp of your vehicle. On a cold start with 10w40 on an 80f day, your oil will be between 10 and 40, NOT 40 at start.

The number is pretty much viscosity range of the oil, nothing more. in 10w40, it can go from 10 to 40. in 5-30, it will go from 5 to 30. Absolute lowest will be 5, absolute highest will be 30. That's all they're saying

there really is a lot of misunderstanding when it comes to oil. The best way to look at it, the first number is whether you want thicker oil at start (on cold OR hot days, it doesnt matter) or not.

 

I can tell you have some understanding of oil.

But you got to think, when the oil is hot, whether it's a 5W-40 or a 15W-40, it's still hot and nearly thin as water. It's going to drain to the bottom of the engine fairly quickly while it's hot until it starts cooling down. All oil will leave a residual film behind.

 

same here lew



And Freakshow its not in my head, been around fords for 20yrs with my 94 being the newest and everyone one i have been around and have tried the 5w stuff just hasnt worked out for me so i have always gone back to the 10-30
each rig has also had over 200k on the motors.

 

Well, I have the opposite experience. And logically, your experience doesn't make sense. But that's ok, to each their own. And to answer the thread, 5W-40 is the best choice to use for an HDEO in the winter time.