5W20 vs 5W30

[Klutch9]

Originally Posted By: Garak
Originally Posted By: TFB1
So how does a 20W enhance warmup when virtually everyone here on BITOG claims a engine will run hotter with a thicker oil...


Rate of temperature increase is not the same issue as final temperature reached.

This /\. Also, thinner oils, as a general rule, have a greater ability to transfer or carry away heat than thicker oils do. This leads to less "hot spots", as the thinner oil will carry heat away more, but also dissipates that heat quicker as well.

In addition, thinner oils also = lower oil pressure at any given rpm (putting aside self-regulated oil pumps) and less resistance on the oil pump, which also helps keep heat lower.

I'm sure I'm leaving a few things out, but that's the general idea.

 

[Whimsey]

Originally Posted By: w6pea
Thanks....being as I go to the desert a lot in the RV I guess I will use the 10/30w. I have a supply of that, A case.

Since you already have a supply of 10w30 use it in your climate, no harm, but not the best. Most 5w30 will perform better, still give you the 30 weight when hot but give you better cold start flow.

Whimsey

 

[chris67]

Your truck can absolutely use the 5w20 and it is backward compatible for all Ford product that spec'd 5w30. In fact there was no appreciable change in engine clearances from 1991, when the first 4.6l modular appeared,to what they are using today. 10w30/40 was the first grade of oil spec'd in 1991 and then 5w30 and now 5w20. Piston to wall and bearing clearance are pretty much the same for 20 years. The new VCT requires people not to miss oil changes like they may have been able to previously. Btw GT 500 mustang specs 5w50 synthetic. Same sort of clearances.

 

[Merkava_4]

Originally Posted By: 4ever4d
Why would it run noisier?


This guy says his 2009 Hyundai Sonata runs noisy on 5W-20 :

Originally Posted By: ryland
They call for 5w20, 5w30, or 10w30 with 5w20 the car sounds very ticky and loud. With the 10w30 it was very smooth and quiet.

 

[steve20]

"""Your truck can absolutely use the 5w20 and it is backward compatible for all Ford product that spec'd 5w30"""

Please post a reference for this prophecy-I'd like to see it

 

[Klutch9]

Originally Posted By: steve20
"""Your truck can absolutely use the 5w20 and it is backward compatible for all Ford product that spec'd 5w30"""

Please post a reference for this prophecy-I'd like to see it


I already posted a link to that bulletin on the first page of this thread. However, as far as ALL Ford products go, not all of the engines were back-spec'd to 5w-20. Most were. I believe the 300 CID I6, along with a few other relatively recently used engines were not back-spec'd

 

[Garak]

Originally Posted By: steve20
Please post a reference for this prophecy-I'd like to see it


You're correct on this. A link was posted previously as to what vehicles are back speced to 5w-20. There are some that are definitely not approved for the back spec. Just about every modular was, as far as I can tell. None of the Town Car/Crown Vic/Grand Marquis 302s were, though.

 

[Klutch9]

I'm surprised that 5w-20 was approved for use on the 302 Mustangs, including the Cobra, but not the 302 in the Crown Vic/Town Car/Grand Marquis. Hmmm... Maybe because the Crown Vic was heavily used by police fleets and Ford felt the 5w-20 was unsuitable for that abuse?

 

[oldmaninsc]

Originally Posted By: Merkava_4
Originally Posted By: 4ever4d
Why would it run noisier?


This guy says his 2009 Hyundai Sonata runs noisy on 5W-20 :

Originally Posted By: ryland
They call for 5w20, 5w30, or 10w30 with 5w20 the car sounds very ticky and loud. With the 10w30 it was very smooth and quiet.


Well, that settles it for me! I'm going to go drain the 5W-20 out of my Grand Marquis right now! What do you suggest I use - 15W40 or 20W-50? /sarcasm

 

[lexus114]

Originally Posted By: Whimsey
Originally Posted By: w6pea
Every time I have had my oil changed in my F250 with a 460 Cid V-8 the Ford Dealership put 10/30w semi synthetic in it. Every time as long as I can remember. I have been going there to get it done since I got screwed at a local service station.
I have had my wife's van run the same oil, as well. I want to change the oil in my Motor Home it's a 2005 it has a V-10 in it. Every time I have had the oil changed the dealer has used 5/20w semi synthetic oil.
I don't think it will hurt it to change to 10/30w as long as I stay with semi synthetic? Any thoughts about changing from 5/20 to 10/30 semi synthetic oil. It must be good oil or Ford wouldn't put their name on it. Does any one know who makes it for Ford Motor Company ? I have over 189,000 on my F-250 and all of those miles I have used the Motorcraft oil and filters in it since 98,000 miles and I don't burn any oil. My wife's van runs the same oil.


I want to do this myself rather than pay the dealer $150.00

when I can do it my self for less than half of that cost.


Motorcraft oil is currently made by ConocoPhillips, quality oil. Your 2005 will run great on 5W-20 oil in any climate or 5w30 in warmer climates if you feel better using it. No need to use 10w30 in any circumstances now a days in a modern gas engine.

Whimsey



+ 1

 

[Garak]

Originally Posted By: Klutch9
I'm surprised that 5w-20 was approved for use on the 302 Mustangs, including the Cobra, but not the 302 in the Crown Vic/Town Car/Grand Marquis. Hmmm... Maybe because the Crown Vic was heavily used by police fleets and Ford felt the 5w-20 was unsuitable for that abuse?


I don't think it was the issue of police use. I'm not sure what the differences are between the CV platform 302 and the Mustang 302 were, but there were differences. Others here will certainly know more about the differences than I will, and I haven't played with any of those engines for a number of years, and I can't remember for the life of me the differences anymore. Different oil pumps? I don't know. The 4.0 L in the Explorer was in the same boat, if I recall correctly.

The 5w-20 did go to fleet use when the modulars came in, with no problems. So it's not just fleet and taxi abuse, and we know that Town Cars don't get routinely pushed to their limits.