Any downside to using 0W - 30 ?

[ThreePedalPlow]

If 0W - 30 is better for cold starting why not use it over 5W - 30 regardless of your climate? Even if you live in a moderate climate wouldn't it be the better choice? I'm also wondering if the engine might idle down faster at startup being the oil is lighter and easier to move around the engine at startup.

Sponsored

 

[roket]

Ford only really recommends the 0W30 when its cold and/or high altitude

 

[timd38]

I worked for an oil company (Fords oil supplier) after I retired the first time, and when I saw all the testing that goes into what the OEMs say to use, I no longer challenge it. Trust me, they don't use a dart board.

 

[Mustang406]

I worked for an oil company (Fords oil supplier) after I retired the first time, and when I saw all the testing that goes into what the OEMs say to use, I no longer challenge it. Trust me, they don't use a dart board.

Ford used to recommend 5w20 on coyotes. Every gearhead on the planet knew 5w30 would be better. I've owned 5 Coyote engines and on the ones that had 5w20 I drained it out after purchase and put in 5w30. Never once have I had BBQ or typewriter tick. Have I been lucky? Maybe. But Ford now says 5w30 in the coyotes. Outside of Shelbys Ford is more interested in fuel economy targets.

 

[Skye]

Thanks for the thread. I've been pondering this question while running errands.

I checked the viscosity scale, how engine oil is measured in the lab. The difference between 0 and 5 is not like between 50 and 55, but between 50 and 250.

Viscosity is a measurement of 1) resistance to flow and 2) shear strength.

I believe it is a given that engines encounter the greatest amount of wear when cold and warming up. Once things are properly up to temperature, conditions within are more stable and better suited for the components.

If operating in a cold climate, let's say Winter, 0 F / -17 C, I'm not to concerned about shear, the ability of the oil to cling or hold onto engine parts. The engine is naturally looser due to cold temperatures. I'm primarily concerned about flow and volume. I want to ensure enough oil is circulating quickly enough to get to all the right places.

In a warmer setting :sun:, Spring, 50 F / 10 C, initial tolerances within an engine are much tighter. Flow of oil is always important, but now I'm concerned primarily about shear, how the oil can hold onto and lubricate parts under those more physically demanding conditions.

Differences in initial tolerances of an engine for the examples above, while measured in thousandths of an inch or less, are meaningful, especially over the life of the engine. Consistently using an oil which is 5X to "thin" or 5X to "thick" at startup is significant.

As noted above, unless you're operating the engine regularly at those much colder temperatures, the Engineers advise use 5W-30. Using something else, IMO, risks premature wear and engine damage.

I can see when using something other than Ford specified (hot or cold) is warranted: when I've modified the engine, for race duty. If I'd taken the engine out and to a shop for mods, I'd pivot and follow their recommendations and experience for oil while using those components under those conditions.

People deviate from my thoughts and use something other-than-specified all the time, with no apparent problems. I'm not confident enough in my abilities (and education) to differ from Ford's guidance. I'll continue to use the recommended weight (5W-30 in my example).

YMMV.

 

[ThreePedalPlow]

Thanks for the thread. I've been pondering this question while running errands.

I checked the viscosity scale, how engine oil is measured in the lab. The difference between 0 and 5 is not like between 50 and 55, but between 50 and 250.

Viscosity is a measurement of 1) resistance to flow and 2) sheer strength.

I believe it is a given that engines encounter the greatest amount of wear when cold and warming up. Once things are properly up to temperature, conditions within are more stable and better suited for the components.

If operating in a cold climate, let's say Winter, 0 F / -17 C, I'm not to concerned about sheer, the ability of the oil to cling or hold onto engine parts. The engine is naturally looser due to cold temperatures. I'm primarily concerned about flow and volume. I want to ensure enough oil is circulating quickly enough to get to all the right places.

In a warmer setting :sun:, Spring, 50 F / 10 C, initial tolerances within an engine are much tighter. Flow of oil is always important, but now I'm concerned primarily about sheer, how the oil can hold onto and lubricate parts under those more physically demanding conditions.

Differences in initial tolerances of an engine for the examples above, while measured in thousandths of an inch or less, are meaningful, especially over the life of the engine. Consistently using an oil which is 5X to "thin" or 5X to "thick" at startup is significant.

As noted above, unless you're operating the engine regularly at those much colder temperatures, the Engineers advise use 5W-30. Using something else, IMO, risks premature wear and engine damage.

I can see when using something other than Ford specified (hot or cold) is warranted: when I've modified the engine, for race duty. If I'd taken the engine out and to a shop for mods, I'd pivot and follow their recommendations and experience for oil while using those components under those conditions.

People deviate from my thoughts and use something other-than-specified all the time, with no apparent problems. I'm not confident enough in my abilities (and education) to differ from Ford's guidance. I'll continue to use the recommended weight (5W-30 in my example).

YMMV.

Thanks for the response. I value your opinion as you seem pretty knowledgeable around here I'm going to stick with the 5W-30. I found a "Garage Box" that is bulk discounted vs what I used to pay for it in the 5 quart jugs. I exclusively used this oil in my Cruze and the cross hatching is still looking really good at 145,000 miles so I think I will use it in the Mustang too. I was thinking about using the FL-500-S in the owners manual but I'm not sure if there are better alternatives for the oil filter or not. The owners manual does say " 1 If a Motorcraft oil filter is not available, use an oil filter that aligns to SAE/USCAR – 36 Performance Specifications. Filter Type C " so I think you could use something else and not void your warranty as long as it meets that criteria. Still trying to find a drain plug that will make future changes easier but I might wait for the next change. Another poster recommended a Form-A-Funnel thing I'm getting to help direct the used oil for now.

Cruze cylinder wall at 145,000 miles:

 

[Skye]

I value your opinion

A generous compliment. Thank You. Lots of great insight from Members here. Some of the forum discussions can get rather "messy", but the majority of the time, we're all looking after one another.

Stellar crosshatch. I've seen some teardown videos on YT and it's amazing what modern spec engines with good maintenance and parts can achieve. Years past, 100K miles / 160 K kms was significant. Now, 200K, sometimes 300K is often witnessed.

Using 1) quality items, 2) consistently following the maintenance schedule and 3) not abusing the mechanics of the car. Lots of great brands to choose from. I think whichever oil a person settles on, unless something is markedly off/wrong, continue to use that brand. At least .5 quart / 475 ml stays in the engine during each change. Different brands often, IDK, I'm not a fan of that.

I'd have zero concerns using Motorcraft. Many GT350 and 500 owners they always use Motocraft items, so there's never a question of warranty. Many with their DD use Motorcraft throughout the warranty period.

I wasn't familiar with USCAR 36, but there's some good, general info available.

The USCAR 36 spec details oil filter construction guidelines. The standard initially arrived in 2013. In 2021, reads like it was updated, to support 10,000 mile / 16,000 km oil changes.

https://www.sae.org/standards/content/uscar36/

https://www.sae.org/standards/content/uscar36-1/

https://www.eurolab.net/en/sektorel...treleri-icin-boyut-ve-performans-ozellikleri/

For filter, it's my belief Ford is transitioning several part numbers. @Carter1776 confirmed the FL-500-S, listed in the Owner's Manual, works well. I've read several other threads saying same. The FL2127 is listed in parts catalogs as supporting the V8, 2024 Mustang. But the FL2127 seems hard to come by. Same threads and gasket face, but the casings of the two filters are a little different in size.

https://www.mustang7g.com/forums/threads/gt-oil-filter-part-number.158400/

 

[LCDRChemEng]

Viscosity is a measurement of 1) resistance to flow and 2) sheer strength.

You probably meant SHEAR strength. My wife sometimes wears sheer stockings and is a sheer terror when she's mad, but her sheer strength is akin to that of a Pomeranian sled dog. Shear strength, on the other hand, is "the ability to resist forces that cause the material's internal structure to slide against itself."

On the subject of 0W30 vs 5W30, I've looked into it briefly. I always follow the manufacturer's recommendation since - like you - I know how much thought goes into it. Then again, if both oils provide the same high temperature protection, and the only difference is flowability at low temperatures, why wouldn't 0W30 be recommended?

To my best understanding, the reason is that both 0W30 and 5W30 exhibit the same pumpability characteristics unless it's really cold, like the ending of "The Shining" cold, which is not a phenomenon I will face in Florida, so not worth the trouble. I will keep to the code until I hear otherwise from Ford. 5W30 is more commonly available and probably cheaper too than 0W30 anyway.

 

[Skye]

You probably meant SHEAR strength. My wife sometimes wears sheer stockings and is a sheer terror when she's mad, but her sheer strength is akin to that of a Pomeranian sled dog.

Ha, correct. Shear. I'll fix that.

Sponsored