Startup question as it relates to 0w20 vs 5w30

[facility1]

oil formulated with moly (trinuclear) with a good balance of boron & star polymers are what many lighter viscosity SQ ,GF_7 engine oils use in regard to other proprietary and common additives in the final blended package, heavier base oils may or may not provide as much starting protection without/or low levels of MO,3 and Boron & VII , but rely more on Zn & ,Ph for wear reduction ,as in diesel oils.,,,,,, correct blending with good base oils and additives/packages can be more difficult on lower viscosity SQ,GF-7 oils as 0w-8, 0w-16 ,,this should be noted also.

 

[lilspenny]

Ok. I have to explain something, and ultimately I have a question at the end.

I decided, to use 5w30 INSTEAD of 0w20 for my new 2025 CX 5 Skyactive engine NON turbo. It calls for 0w20 , but due to cafe standards and many opinions, i went with 5w30 on my first oil change.


I live in Texas where its cold now but NOT brutal winters.

My reason for switching to 5w30 is because its supposedly provides slightly more wear protection overall, based on my research.Better for engine, not for cafe standards type of thing.


Having said all that, here is my question:

If it is true that 90 percent of engine wear occurs at STARTUP, and 0w20 gets to the engine QUICKER at startup, doing the math, does not this make the 0w20 a better choice then, no matter what tests show 5w30 is better overall (while driving etc)?



Make it make sense!

This may or not satisfy your quest for knowledge but it may give you some valuable info...

 

[YZJB]

Thats really interesting.. I bet the engines are quieter.. and is this in areas that get really cold?

Not much of Australia gets particularly cold.
Below-freezing is rare, maybe a few times each winter in the southern states. Up north barely gets below 15-20 degrees C.

 

[kschachn]

Thats really interesting.. I bet the engines are quieter.. and is this in areas that get really cold?

Quieter because of a winter rating that isn't anywhere near the limit?

 

[kschachn]

My reasoning is that Texas does not get hard cold winters where i am at if it gets to 20 degrees farenheit its rare.. it DOES get cold here , very cold at times but not like northern states.. so i figure why not just stick to the oil that seems to be better for wear overall.. thats my reasoning anyway

At those temperatures any winter rating is appropriate. Any.

 

[tolian21]

Go with a 0W-30. Best of both worlds!

I agree, but the big problem with 0w-30 is that your oil choices are going to be very limited compared to 5w-30

 

[50yr Street Mech]

In my old / high mileage Honda K24, I run 0W20 from Dec-March, then 5W30 the rest of the year. We do get some pretty bad cold snaps in NY. I also let the engine warm up a bit during the winter. No problems with the engine using this approach.

 

[Hohn]

I agree, but the big problem with 0w-30 is that your oil choices are going to be very limited compared to 5w-30

Choice is pretty overrated unless you can't find something that works well. The numbers of options is only relevant with the first option isn't good or won't work.

If you can't find 0w-30 anywhere and it's only available at great inconvenience, that's one thing. But if there's only one choice and it's Mobil 1 ESP and it's in several local stores, that's quite another.

 

[facility1]

AMSOIL Signature Series has a excellent 0w-30 you can get delivered to your door, plus take advantage of the preferred customer pricing or use Pennzoil Ultra Platinum 5w-30 as it runs on the thinner side of this weight and also is a stellar oil, found at most Walmart stores.

 

[Ride_Red]

I have a 24 Rav4 with the 2.5 I4 ICE engine that is spec'd for 0W-16. I used 0W-20 for most of the oil changes for the first 20K miles (except the free dealer ones of 0W-16). This past summer (2025) I used Pennzoil Platinum 5w30 for 5K miles since I was towing a motorcycle trailer and sometimes a 16' aluminum fishing boat. The Rav4 towed both quite well and the engine didn't use any oil over a 5K mile run. I recently switched back to 0W-20, both because I had it in the garage from a rebate and because it is now winter and I'm not towing. I plan to switch the Rav4 back to 5W-30 in the spring for towing season. Maybe once I use up my rebate stash I'll look for a quality 0W-30 and just run that all year.

Subjectively, whenever I have switched from 5W-30 oil to 0W-20 oil in the cold weather, I have noticed a bit less startup rattle with the 0W-20 on initial startup on cold Michigan winter mornings. This has been consistent with the 24 Rav4 and my 10 CR-V. I've used 0W-20, 5W-20 and 5W-30 in the CR-V over the last 15 years. I also noticed a difference in the length of startup rattle in my old Chrysler minivans when switching from 5W-30 to 5W-20 in the cold weather.

 

[Bojo]

I have a 24 Rav4 with the 2.5 I4 ICE engine that is spec'd for 0W-16. I used 0W-20 for most of the oil changes for the first 20K miles (except the free dealer ones of 0W-16). This past summer (2025) I used Pennzoil Platinum 5w30 for 5K miles since I was towing a motorcycle trailer and sometimes a 16' aluminum fishing boat. The Rav4 towed both quite well and the engine didn't use any oil over a 5K mile run. I recently switched back to 0W-20, both because I had it in the garage from a rebate and because it is now winter and I'm not towing. I plan to switch the Rav4 back to 5W-30 in the spring for towing season. Maybe once I use up my rebate stash I'll look for a quality 0W-30 and just run that all year.

Subjectively, whenever I have switched from 5W-30 oil to 0W-20 oil in the cold weather, I have noticed a bit less startup rattle with the 0W-20 on initial startup on cold Michigan winter mornings. This has been consistent with the 24 Rav4 and my 10 CR-V. I've used 0W-20, 5W-20 and 5W-30 in the CR-V over the last 15 years. I also noticed a difference in the length of startup rattle in my old Chrysler minivans when switching from 5W-30 to 5W-20 in the cold weather.

thats interesting...at what temp do you notice the difference in startup rattle? We left Michigan because of the cold winters btw

 

[Bojo]

AMSOIL Signature Series has a excellent 0w-30 you can get delivered to your door, plus take advantage of the preferred customer pricing or use Pennzoil Ultra Platinum 5w-30 as it runs on the thinner side of this weight and also is a stellar oil, found at most Walmart stores.

I didnt know Pennzoil Ultra Platinum ran on the thinner side of 5w30... thats interesting how do we know this though? I havent seen anything on that..

 

[rstsco]

I didnt know Pennzoil Ultra Platinum ran on the thinner side of 5w30... thats interesting how do we know this though? I havent seen anything on that..

Go to the Virgin Oil Analysis section and search "Ultra", then look at the threads showing 5W-30 in their title. The VOAs show 5W-30 Pennzoil Ultra Platinum is at the bottom end of the 30 viscosity scale.

Added: Look for Viscosity cst@100C

 

[Ride_Red]

thats interesting...at what temp do you notice the difference in startup rattle? We left Michigan because of the cold winters btw

Below freezing temperatures, typically. We get some mornings in the single digits F or negative digits F and it is definitely noticeable. 20F-30F it really isn't noticeable.

 

[Ride_Red]

I didnt know Pennzoil Ultra Platinum ran on the thinner side of 5w30... thats interesting how do we know this though? I havent seen anything on that..

You can look on the oil mfgr's website and get the data sheets for their oil. Most mfgr's (Pennzoil, Mobil, Castrol, etc) publish the 40C and 100C viscosity along with other data you can compare to get an idea if it runs thick or thin for the grade.

 

[cheesepuffs2]

My reasoning is that Texas does not get hard cold winters where i am at if it gets to 20 degrees farenheit its rare.. it DOES get cold here , very cold at times but not like northern states.. so i figure why not just stick to the oil that seems to be better for wear overall.. thats my reasoning anyway

What’s “very cold” in Texas terms? That’s an honest question, not being facetious.

 

[rstsco]

What’s “very cold” in Texas terms? That’s an honest question, not being facetious.

Texas is a bit larger than other US states, therefore spans many temperature zones. The panhandle can and does get below 0F during the winter.

Living in the Austin area, when our temps are forecast to get into the upper 20s F, the weather-guessers are telling everyone to "Bring in your cats and dogs! It's going to be a cold one tonight!"

I grew up in eastern Oklahoma and spent five winters in Omaha, Nebraska while in the Air Force, so I know what real cold feels like.

True story: I lived in base housing when in Omaha and was a midnight-shift supervisor. I went out to start my car about 10pm and the oil light came on. Quickly turned off the engine and looked underneath the car. The oil filter had separated, dumping out all the oil. Got a neighbor to take me to an overnight supermarket that also sold oil and filters. Changed the filter, added oil, and off to work I went. Oh yeah, the temp was close to -20F with a wind chill over -50F.

 

[Bojo]

Go to the Virgin Oil Analysis section and search "Ultra", then look at the threads showing 5W-30 in their title. The VOAs show 5W-30 Pennzoil Ultra Platinum is at the bottom end of the 30 viscosity scale.

Added: Look for Viscosity cst@100C

Will definitely check that out! Thanks!!

What’s “very cold” in Texas terms? That’s an honest question, not being facetious.

Great question. . where I am at it RARELY gets to 20 and often in the 40s 50s during "winter".... Where I used to live it consistently got below freezing and even in negative temps.. i would consider that very cold.

 

[kschachn]

You can look on the oil mfgr's website and get the data sheets for their oil. Most mfgr's (Pennzoil, Mobil, Castrol, etc) publish the 40C and 100C viscosity along with other data you can compare to get an idea if it runs thick or thin for the grade.

They publish “typical values” which are unrelated to any particular batch or lot. As noted some of the ones you’re listing print specification limits and don’t represent the specific product at all.

 

[Ride_Red]

They publish “typical values” which are unrelated to any particular batch or lot. As noted some of the ones you’re listing print specification limits and don’t represent the specific product at all.

True, but that is about all a typical consumer has available to look at. A VOA will most likely be from a different lot, or formulation, than the jug someone grabs off the shelf at Walmart.