Originally Posted By: 2010_FX4
I agree with you, however, unless I am mistaken, the "argument" is that 5W-20 is not sufficient even in engines that were specified for it. Somehow the discussion changed from a vehicle that was specified for 5W-20 to those that were not and that is the reason I posted the information about the 6.2/6.8L engines. I would assume the power density between a 5.4L and 6.2/6.8L is vastly different and yet 5W-20 is still more than adequate for those larger engines pulling more than double the weight noted in the disclaimer for the back specified 2V engines.
Power density is simply a fancy way of saying HP/L. The 2V 5.4L made 260HP, which is 48HP/L. The 4.6L 2V in the Mustang also made 260HP, so 56HP/L.
The later 3V 5.4L made 300HP, so 55HP/L.
The 6.2L makes 62HP/L, the 6.8L V10 makes 45HP/L. These are all relatively low power density applications.
And the 4.6L Crown Vic even in PI trim was only 240HP, so 52HP/L.
So you have some rather low power density engines with large sumps and factory oil coolers.
And the 3V 5.4L received an upgraded higher volume oil pump over its back-spec'd (and caveat bearing) 2V sibling.
If you were somehow able to push the envelope far enough to elevate oil temps beyond the designed operating range, then a heavier oil WOULD offer more protection. And this is why Ford included that caveat for the 2V engine. They obviously did enough testing to determine that this was the case with that engine. This also means Ford did some significant homework prior to back-spec'ing engines.
Quote:
Even for the engines that are specified to use 5W-20 (such as the Camry in the example), there is still a stigma that 5W-20 is not good enough and therefore XX-30/40 must be used. In my short time on the board, I see (more or less) X-20 lovers or haters and not very many in between. I am not a 5W-20 lover per se, I am using the designed oil specification for my vehicle, if 5W-30/40 was specified I would use it, but since 5W-20 was, I use it. I guess I question when x-20 WILL be "good enough" to join the ranks of the hallowed xx-30/40 oils and thus will no longer be viewed as a consequence of a regulation change.
As I'm sure we can all agree, viscosity is not static and varies greatly with temperature. As long as we remain within the safe temperature range for 5w20 to provide adequate protection, then that is exactly what it is going to do.
HOWEVER
If through driving style, operating conditions....etc we are SOMEHOW able to elevate oil temperatures beyond that safe range, then a heavier lubricant is REQUIRED to provide adequate protection at this point.
Ford did a LOT of testing regarding 5w20 under EXTREME usage conditions and used the formula I outlined above to successfully allow the use of this lubricant in truck and LEO applications.
So that begs the following questions:
1. Does a Camry that spec's 5w20 have a larger sump?
2. Does it have an oil cooler?
3. How much did the intended target audience affect Toyota's level of "abuse-proofing" the Camry compared to something targeted at younger, likely harder-driving individuals?
The CVPI was designed for LEO and Taxi use. It has a large sump and as 95busa mentioned, a plethora of additional coolers to cope with its intended use.
The same can obviously said for Ford trucks.
The Mustang however, even WITH the factory oil coolers and increased sump, because of its much higher power density, STILL ends up being spec'd for 5w50 in BOSS 302 form, whilst its nearly identical brother, the Mustang GT, calls for 5w20.
Does this not raise the same target audience and intended use questions I raised about the Camry?
It isn't as black and white as we'd like it to be
