edyvw
$50 site donor 2026
There are numerous topics on this. Oils like 0W20 or 5W20, or ILSAC 30 grade are there for fuel economy, to meet CAFE standards.
If FORD is out of warranty, run ESP 0W30.
Genesis 0W-30 Vs 5w-30
- Thread starter Shrike9
- Start date
If FORD is out of warranty, run ESP 0W30.
I’m still trying to muddle my way through all the different oils and grades & such and Mobil 1 recommending almost the same oil I’m running in the 7.3L gasser caught me off guard
it will be under warranty
Why can't we? It does. An oil with a higher HT/HS always reduces wear. It also provides some margin for fuel dilution which is common in many engines these days. This is the primary reason I use 504 00 oil in my Tiguan as opposed to 508 00.
The only upside to a thinner oil is a marginal decrease in fuel consumption. Other than that there are no real benefits. This whole "heats up in the bearings" is a non-issue with the grade increases we are talking about here.
I suggest reading the post you quoted once again. It is brief, should not be that hard to comprehend
I am finding it hard to comprehend why the guy in your avatar is dumping new oil into an oil drain pan. Then I realized it makes about as much sense as your HTHS argument that being thicker it generates enough extra heat to provide less protection.
Yeah i guess that is one way to look at itI am finding it hard to comprehend why the guy in your avatar is dumping new oil into an oil drain pan. Then I realized it makes about as much sense as your HTHS argument that being thicker it generates enough extra heat to provide less protection.
View attachment 309877
And much better cold start, especially if the car is kept on the streets.
Arguable. Not sure that esp 0w30 is " Much Worse" than ... Mobil 1 Advanced Fuel Economy 0w30 at -20f. (or even -35f)
considering the superior components of Mobil 1 ESP.
yet one is 10.5cst@100c and would never stay in grade in my car.. while the other will with its near 12cst@100c viscosity.
I was talking in general like 0W-20 vs 5W-30, not particularly for these two oils. The first one has much better cold start, especially below 10*F.
Mobil 1 ESP 0W-30 has very low pour point at -51*C/-60F (per Mobile website), however its viscosity at 40*C and below will always be higher than any 0W-20 oil.
Oil becomes thicker at low temp much earlier than its designated pour point. So, if any oil has pour point at -40*C or -50*C per its PDS, that doesn't mean that at -20*C that same oil lubricates in the same way and put the same load on the oil pump as at -10*C, for example.
It doesn't keep its optimal lubrication all the way down to its pour point is what I'm trying to say.
My comment addition to this one, so I don't
want to drag the thread in off topic:
edyvw
$50 site donor 2026
The cold start is measured differently.
Mobil1 does not publish CCS and MRV data, so we don't know what the results are. Just because oil is thicker at 40 °C or 100 °C, does not mean CCS and MRV are worse.
What we know is that ESP has more PAO which helps a lot with winter performance
Why not?
If an oil has particular viscosity at 40*C which is higher than other oil at the same temperature, what makes the first oil perform better (in terms of cold start) at even lower temperatures?
edyvw
$50 site donor 2026
That is why CCS and MRV are used instead of measuring kinematic viscosity, pour point.
5W30 ILSAC oils are definiately thinner than Mobil 1 Full Synthetic 0w40 at 40c and 100c, but 0W40 is well, 0W.
There is a big fan base of thick oils around here. An oil having marginally higher HTHS will provide enormous protective benefits when hot, but thinner being able to lubricate better at the startup, which I believe universally agreed where the most wear happens, will only provide negligible benefit, if any from that vantage point.
I wish the world would be as simple as "thicker = more protection" and we would all get 20w50 oil and call it a day.
Exactly. So if the film is already thick enough to cover surface imperfections and then another 2 layers between materials, what is the benefit of having a thicker film?
In engineering, optimal almost never means maximal. One should not take that dogmatic "we need thicker and thicker films for protection." because it just leads to uncessary stress. You want the thinnest film with adequate protection. But hey, that does require some thinking, and who wants that
The problem is you don’t know when it’s going below MOFT. It’s not a catastrophic failure, it’s something that doesn’t show up until later in the vehicles life. Lower oil pressure, upper rod bearings worn through a layer, etc. The extra headroom of a higher grade has no downsides. Possibly a undetectable mpg hit.
Would Ford actually reject warranty because of 10w viscosity difference? 0w-20 vs 0w-30? I doubt it. With a very high quality oil? I guess I myself would upgrade to 30w. CAFE standard be darned.
Like my relatives that work at a Lexus dealership and the other that worked at a Porsche/Audi dealership both said to me. All we check is you are not running ATF, gear oil, and the correct level and your oil is somewhat clean if their is a engine warranty issue. Both places have never used oil analyses to void warranty if it was the above criteria as far as engine oil car oil. They have pulled them with anything not normal in the car. Both have worked there for 10+ years. The Porsche/Audi guy was an order writer, so he saw all the back and forth on all issues directly between the customer/dealership. Now catching "tuned cars" under warranty was a big deal for them, just not oil if it meet the simple criteria above.
Right, but there are plenty of folks out there running thinner oils in cars well over 200,000 miles. I agree that there is wear that you won’t find out about until very late in the game, but not seeing evidence that folks are doing better with the thicker oils. In fact, we can surmise that the vast majority of folks are following the mfr recs. Would this not mean that the outliers would be obvious?
I agree most will never know the difference or ever keep the car long enough to know. When I was working at the dealer it was mostly seen in hard working fleets. My personal vehicles are always in severe service so it’s a no brainer for me.
Similar threads
