5W-30 in Ford 2.5L, 3.3L, 3.5L, 3.7L?
- Thread starter Fordiesel69
- Start date
My 454 engine I built engine runs about 2.5 thousands clearance on the rods and mains, that's tighter than any production engine and it runs 30 weight oil... So now what?
This is another-useless "Thick vs. Thin". I'm not going there....as I mentioned above.
It no thick vs thin it's all based on operating temperature and viscosity.
Before the 1960s, probably by WW2 mechanic engineers had figured out that the ideal viscosity for engine oil was 10 to 12 cSt at operating temperature.
Most engines run about 190 to 230f oil these days; that puts a 30 weight oil at about 9 to 12cSt.
Heavy duty diesel and air cooled engines run 40 and 50 weight oils because the oil gets hotter, in that 230 to 260f range you want a 40 weight oil, a 40 weight oil will be around 10 to 12cSt at those temperatures. Above 250f run a 50 weight oil so you're oil thins out to that 12cSt range when hot.
Prior to multi grade oils people up north would run 20 weight oil just so their cars might be more likely to start.
20 weight oil wasn't killing any engines back in the 1950s either. Probably because 20 and 30 weight oil has some cross over in their viscosity grading spec. You can also have a 20wt and a 30wt both test as 9cSt at 212f, but ones in a bottle that says Xw-20 and the other says Xw-30, just because they can.
Then when multi grade oils were introduced people just didn't intentionally run 20wt oils in engines any more, not again for nearly 50 years until the unholy quest for cafe numbers started.
- Joined
- Aug 4, 2024
- Messages
- 4
Maybe this help you feel better about 5w-20. This is a police cruiser I work on. This is a 2014ish? Explorer 3.7. Yes the hours are correct. This has been ran on Mobil synthetic blend its whole life. Running a motorcraft FL500s filter. Never had chains or timing components done. It’s had a water pump once in its life. But that’s it.
dnewton3
Staff member
Other than the water pumps being internal in transverse applications (hence expensive in labor to change), the Cyclone engines are very robust and long-lived. They actually run very clean (not a lot of soot/sludge) and they have good power for their size. The longitudinal applications (F series and Mustangs) make the pump change much easier.
A GM 5.3 is not a diesel, nor a Cummins.
I pulled apart an OEM 454 over the winter that was <.0025" on all rod and main bearings. They varied from .0019-.0023". It had ~70k miles on it.
Many engines have/had less than .0025" clearance from the factory. In fact, there's only been maybe 2 or 3 I've torn down that had >.0025" clearance, and they were severely worn.
Ease up on the hostility. It won't get you far here.
Forget about it if you’re not using a $77,000 speaker cable with “solid tellurium copper connectors”:
https://www.transparentcable.com/products/magnum-opus-speaker-cable
Still has a similar cam, lifter, pushrods, rocker to valve for the valve traine, still has cast iron cylinder bores, hypereutectic aluminum pistons, both have similar molybdenum plasma coated piston rings, both likely have chrome oil rings.
Yes I understand some people are allergic to facts.
But thanks for confirming there's nothing special about "tight tolerances" on modern engines.
OVERKILL
$100 Site Donor 2021
Exactly. There have been a ton of accommodations made to ensure that engines are able to survive on thinner and thinner lubricants. Wider bearings, high durability coatings, special materials...etc. On top of that, the additive package is required to meet the performance requirements of these changes and these characteristics with the API imposed limit on phosphorous, which has resulted in the use of other compounds to improve AW performance.
By and large engines haven't gotten any tighter. People toss out "tighter tolerances" when they typically mean clearances. Arguably, the shift from hand-fit pistons to bulk fit actually loosened up the tolerances on these components, allowing for a greater range of clearances. This was apparent with the LSx engines and piston slap, as well as with Ford's Modular engines. The combination of short skirts (lower friction) and the potential stack of a wider permitted piston-to-bore clearance and increased tolerance for this due to the bulk-fit method resulted in a considerable number of engines being very noisy on cold start. The "solution" was teflon coating on the skirts, to dampen the noise, but of course it eventually wears off, so they do often become noisy eventually.
Some examples from production:
- The 5.7L (mass produced) vs 6.4L HEMI (more niche). Both have the same clearances, one now spec's 0W-20, the other 0W-40.
- The 5.0L Coyote in the Mustang, spec'd 5W-20, Track Pack version of the same car, with the same engine? 5W-50.
- The S62 engine originally spec'd a ~3.5cp HTHS 5W-30, was updated to 10W-60 to reduce oil consumption (post 03/00 cars in ROW were re-spec'd LL-01).
What we won't see is the back-spec'ing of engines not designed for them, to super thin grades like 0W-8 and 0W-12, because the engines designed for those grades have the aforementioned accommodations made, like wider bearings, which are critical for survival with an extremely low HTHS. This was mentioned in the infamous Honda paper that @Shannow quoted from "back in the day".
I believe Ford did this for all of their EB engines as they started seeing engine issues with the 5w20 oil.
I would run a 5w30 personally with no more than a 5k OCI. Completely ignore the OLM. These are very hard on oil being DI and twin turbo.
I think if a top shelf 20 grade was used, it would be fine, but Ford has to assume the owner is ignorant in this regard and will buy the cheapest off-brand conventional 20 grade they can find. Plus, Motorcraft oil (like most all shelf oils) isn't anything to write home about. I did a study with a friend's Mazda GDI engine that was OEM 5W-30 fill. At 5k miles and 4.5% dilution with both, HPL PCMO 10W-20 had a higher KV100 than the OEM fill 5W-30.
Ran 0w20 in my Mazda 2.5L MZR (Ford Duratec clone) for 150K miles. At 150K miles I switched to a 5W30 at the recommendation from an old time mechanic who said it was not a bad idea at the higher mileage it had. Ran the 5W30 until 202K miles when I traded her in. Never burned a drop of oil. Great engine.