[Chris-Austria]

Originally Posted by AdamIsAdam

Did they say why?

As for 5W-50, why doesn't every oil have a really wide range? I thought I read a reason why they don't years ago but, well, I don't remember breakfast, so.

I understand why new engines are made for lower weights, but why not make everything use 0-xx?

The owners manual of my 66 GTO says that 10w30 or 5w20 is an acceptable alternative to the straight 20w or 10w. 20w50 is even thicker than the factory recommended.

A really wide range in viscocity is only possible with synthetic oils like the modern types. You probably could use 0w40 as well.. I never tried. The Morel lifters (HR) recommend 5w40 for the ones I bought... Butler said I can use 20w50.. I trust them but I think where I live I don't want a thick oil at startup all the time.

Maybe a synthetic oil will leak more if you run stock gaskets or if they haven't been replaced for a long time.. oil pressure with the 5w50 is also about 5psi more when really hot compared to the 15w40 I used for break-in.

[Formulajones]

Again, you have to look at the pour values if you want a real look at the cold operating temps. Not all 20w-50's are the same, not even close. If Butler recommended that viscosity for your engine, then go through the list and find your favorite brand that has a pour value that works in the climate you live in.

There are a few good 20w-50's that will work in extremely cold temps, and some of the 20w-50 brands are better in the cold than some 10w's in other brands because the additive packages are simply better with some brands. So it pays to look at the pour values.

[AdamIsAdam]

Originally Posted by Formulajones

Again, you have to look at the pour values if you want a real look at the cold operating temps. Not all 20w-50's are the same, not even close. If Butler recommended that viscosity for your engine, then go through the list and find your favorite brand that has a pour value that works in the climate you live in.

There are a few good 20w-50's that will work in extremely cold temps, and some of the 20w-50 brands are better in the cold than some 10w's in other brands because the additive packages are simply better with some brands. So it pays to look at the pour values.

Originally Posted by Formulajones

Here is a chart that backs up what Adam is saying. First column is 20w-50 oils and their pour ratings. Notice how not all 20w-50 oils are the same.

http://mcgeerf.tripod.com/americansy...coil/id17.html

And based on this chart, even the 20W-50 Valvoline Race dino oil pours at -10*F. And I don't know about you all, but my car is: 1) garaged, which means even if it were -10*F outside, the oil in the engine wouldn't be that cold, and 2) IF IT'S -10*F I SURE AS SH1T AM NOT DRIVING MY PONTIAC!

Formulajones, what is your take on the "ash" rating on that chart?

[JSPONT]

You mean you guys don't have heated garages?? the coldest my car gets even when it is 0 outside is 54 degrees. I have radiant heat, LOL I keep it low to save $$

[Formulajones]

Originally Posted by JSPONT

You mean you guys don't have heated garages?? the coldest my car gets even when it is 0 outside is 54 degrees. I have radiant heat, LOL I keep it low to save $$

Not needed here in Arizona

[AdamIsAdam]

Originally Posted by JSPONT

You mean you guys don't have heated garages?? the coldest my car gets even when it is 0 outside is 54 degrees. I have radiant heat, LOL I keep it low to save $$

Yup, mine's got heat. but I only turn it on when I'm going to be working in there. However, the garage stays pretty warm regardless. It's only got 2 outside walls (including the door) and also the brick chimney runs through it, exposed, on one wall. come to think of it, that probably does a lot to keep the temps so warm in there. I'll have to put a thermometer in there to see what it actually is.

Radiant heat? nice. Floors or just regular radiators on the walls?

[JSPONT]

Originally Posted by AdamIsAdam

Yup, mine's got heat. but I only turn it on when I'm going to be working in there. However, the garage stays pretty warm regardless. It's only got 2 outside walls (including the door) and also the brick chimney runs through it, exposed, on one wall. come to think of it, that probably does a lot to keep the temps so warm in there. I'll have to put a thermometer in there to see what it actually is.

Radiant heat? nice. Floors or just regular radiators on the walls?

Floors, when I lay on the floor under the car its nice and toastie. I can put a separate thermostat but I just run it off my den. My den is at 70, so when its real cold out the garage is 54. 13.5" ceiling. Hell I even have a/c for the summer!!

[Formulajones]

Adam,
The lower the number the better. I do know that high ash content tends to create more sludge build up over time so it's definitely a number to pay attention to, especially if you extend your oil change intervals.

I don't see Brad Penn on that list, and I know that is also an excellent oil with low ash and good pour qualities.

I'm with ya on the temp thing. I used to live in Cinci so below zero temps during winter were common and not much temp change during the day didn't help either.
Here in the upper elevations of Arizona now and the really cold winter nights are only in the teens for a short couple weeks (day time winter temps 50-60). So most of the time I don't have to worry about super cold mornings. Right now it's 36 outside and they are forcasting a high of 72 today. Very big temp swings out here in the desert. So I pay attention to oils with good cold start properties as well as high temp operation that I can run year round, since winter is very short here (the cold winter temps are pretty much over for us now and trees are starting to bud) Summers are 100+ degrees and the nights drop to 60-ish.

[1968GTO421]

[QUOTE=Formulajones;5695673]Adam,
The lower the number the better. I do know that high ash content tends to create more sludge build up over time so it's definitely a number to pay attention to, especially if you extend your oil change intervals.

I don't see Brad Penn on that list, and I know that is also an excellent oil with low ash and good pour qualities.]

Speaking of ash and sludge, back in the '60's and '70's, ash was a concern as it could really foul plugs if burned and no one wanted sludge buildup. Back then Quaker State was reputed to be sludgiest. The lowest ash oil was Valvoline made from Kentucky oil stock back then = racer's choice.

[Chris-Austria]

Originally Posted by Formulajones

Again, you have to look at the pour values if you want a real look at the cold operating temps. Not all 20w-50's are the same, not even close. If Butler recommended that viscosity for your engine, then go through the list and find your favorite brand that has a pour value that works in the climate you live in.

There are a few good 20w-50's that will work in extremely cold temps, and some of the 20w-50 brands are better in the cold than some 10w's in other brands because the additive packages are simply better with some brands. So it pays to look at the pour values.

I think the pour values highly depend on if the oil is synthetic or mineral.. you can see it here: https://www.youtube.com/watch?v=MVn5OzuHtjg

The advantage of a 5w50 over a 20w50 is that the 5w50 will flow a lot better when most of the engine wear occurs.. at cold start.. even if the garage is heated, the 20w50 will be outperformed by far. And when hot, both are about the same... but the 5w50 is synthetic, so it won't age as fast and it will not suffer from the heat as much as a mineral oil.

I'm also pretty sure that the synthetic types also have a better ash rating in most cases.

[Formulajones]

Originally Posted by Chris-Austria

I think the pour values highly depend on if the oil is synthetic or mineral.. you can see it here: https://www.youtube.com/watch?v=MVn5OzuHtjg

The advantage of a 5w50 over a 20w50 is that the 5w50 will flow a lot better when most of the engine wear occurs.. at cold start.. even if the garage is heated, the 20w50 will be outperformed by far. And when hot, both are about the same... but the 5w50 is synthetic, so it won't age as fast and it will not suffer from the heat as much as a mineral oil.

I'm also pretty sure that the synthetic types also have a better ash rating in most cases.

It depends on which brand oil you use. They are all not the same. 5W-50 doesn't necessarily have an advantage over some of the 20w-50's in cold weather when you compare the pour values.

Just look at 20w-50 Amsoil, Redline, and Royal Purple with pour values of -47 -49 and -44 respectively. I don't know where you are but most of us in the USA don't deal with temps like that, and there are quite a few 5w oils on the list that aren't this good, and even some of the synthetics on the 5w list are barely scored the same.