5w20 vs 0w20?

[Mad_Hatter]

Originally Posted by kschachn
Pour point is not a reliable indicator of cold-weather cranking performance, the 0W rated oil will be better at very low temperatures. As you note, below -25F or even colder. Up until then there's really no way to predict which one might be slightly better.

Right, i get that. But mfgs don't always publish mrv (as previously stated) so you get what you get. You base your decision on whatever you have to work with and if all you have to work off is pour point, well pour point it is. It's better than nothing/guessing.

Both the 5w20 and 0w20 are likely using similar Grp4/5 base stocks (maybe some grp3 for "cheaper" 0wX brands??), the difference (I'm guessing here) is going to be in the amount of VII's. Since VII's are a non starter at low temps (correct??), can we surmise that the cold flow characteristics will be very similar up to the very extreme end of the scale (-below -30/35c??)

 

[4WD]

Well, I run 0w20 with confidence in Texas … so it would be an easy "decide" if I lived in International Falls …

 

[derass]

We got down to -35 °C a few times this winter. My car was pretty slow to crank then. But I'm not sure if the 0W oil would help, or if it was just the small, stock 51R battery. I've been considering a BCI 35 AGM battery upgrade too.

 

[NH73]

I had a mechanic told me that 0w20 wears down your cylinder walls and they try to avoid that. I asked what they use in place and the reply was 5w20. My take is 5w20 would do the samething. Truth or lore?

 

[ka9mnx]

Originally Posted by NH73
I had a mechanic told me that 0w20 wears down your cylinder walls and they try to avoid that. I asked what they use in place and the reply was 5w20. My take is 5w20 would do the samething. Truth or lore?

Your mechanic is misinformed. They are both a 20 grade when the engine is warmed up.

 

[NH73]

Originally Posted by ka9mnx
Originally Posted by NH73
I had a mechanic told me that 0w20 wears down your cylinder walls and they try to avoid that. I asked what they use in place and the reply was 5w20. My take is 5w20 would do the samething. Truth or lore?

Your mechanic is misinformed. They are both a 20 grade when the engine is warmed up.
I have a job where I get a chance to talk to numerous mechanics, so no this is not my mechanic. But your reaffirming what I thought. But why would they think this way.

 

[OVERKILL]

Originally Posted by NH73
Originally Posted by ka9mnx
Originally Posted by NH73
I had a mechanic told me that 0w20 wears down your cylinder walls and they try to avoid that. I asked what they use in place and the reply was 5w20. My take is 5w20 would do the samething. Truth or lore?

Your mechanic is misinformed. They are both a 20 grade when the engine is warmed up.
I have a job where I get a chance to talk to numerous mechanics, so no this is not my mechanic. But your reaffirming what I thought. But why would they think this way.


Because most of them don't understand the viscosity grading system.

 

[Patman]

Originally Posted by derass
We got down to -35 °C a few times this winter. My car was pretty slow to crank then. But I'm not sure if the 0W oil would help, or if it was just the small, stock 51R battery. I've been considering a BCI 35 AGM battery upgrade too.


You must be a lot further north than Toronto then, because the coldest day in Toronto (or the GTA) was only about -22C last winter, in fact I've never seen it get below -25C here, let alone -35C. And at -22 I had no problem with 5w20.

 

[Garak]

Originally Posted by derass
What about in cold-weather? Honda changed the oil spec of my Accord after a few years and it gets pretty cold here, so I'm switching to 0W.

There's nothing wrong with a 0w-XX. It'll work fine, and if you're buying a synthetic already, it won't cost more. Nonetheless, I've used 5w-XX most of my life in Saskatchewan with only a few forays into 0w-XX territory.

 

[D1dad]

Originally Posted by Patman
Originally Posted by derass
We got down to -35 °C a few times this winter. My car was pretty slow to crank then. But I'm not sure if the 0W oil would help, or if it was just the small, stock 51R battery. I've been considering a BCI 35 AGM battery upgrade too.


You must be a lot further north than Toronto then, because the coldest day in Toronto (or the GTA) was only about -22C last winter, in fact I've never seen it get below -25C here, let alone -35C. And at -22 I had no problem with 5w20.


Then your the reason it was -22 in Ohio last year lol. I stayed in and didn't attempt to start a car and my diesel truck flipped me off when I plugged it in.

 

[earthbound]

-22c is not that cold (-7f)