Is there any advantage/disadvantage to using a 5W-30 over 10W-30 synthetic.
Thanks
ANY ADVANTAGE
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A 5w30 will generally get better mileage than a 10w30.
A synthetic will shear less than a dino, especially in 5w30 weight.
Patman
Staff member
Based on many UOAs we've seen on here, I would honestly say that there is almost no need for 10w30 synthetics anymore, since a 5w30 synthetic can do everything a 10w30 can plus it will then also flow much better in the cold.
With some oils (like GC or Amsoil), you might as well even go with the 0w30, since you'll get even better cold cranking, but will lose none of the hot viscosity at all (in other words it won't thin out over the interval)
With conventional oil it's a different story, since 5w30 dino thins out way too easily, while a 10w30 dino is much more stable.
But in Texas there is simply no need for a 5W oil (IMHO)
Patman
Staff member
quote:Even if it only gets down to 40 or 50, the 5w30 could help.
Originally posted by Al: But in Texas there is simply no need for a 5W oil (IMHO)
Most of my local customers here in Alabama run the Amsoil 0w-30 instead of their excellent, 10w-30 synthetic. I'd highly recommend running any shear stable 0w-30 instead of a 10w-30 in order to optimize fuel efficiency and engine performance. I'd also recommend running a fuel efficient 5w-30 or 5w-40, synthetic diesel oil instead of a 15w-40 in order to save fuel. In applications calling for 5w-20 oils, I'd also use a 0w-30 synthetic since it "brackets" the viscosity of the recommended lube.
Even in a mild climate, a 0w-30 is going to flow easier on a cold start and will reduce the load on your battery.
It will also provide significant fuel savings during the warmup period.
Tooslick
www.lubedealer.com/Dixie_Synthetics
Patman
Staff member
I want to turn this around the other way, since I'm really curious as to people's thoughts on this:
What advantages do a 10w30 synthetic have over a 5w30 synthetic? I say none, since a good 5w30 synthetic will not thin out.
quote:Great question. But the qualifying statement in your question is "since a good 5w30 synthetic will not thin out". If the oil is good quality, I don't forsee much difference at all. Howerver, as we all know better here at BITOG not all "synth's" are made equal, thus relying in VIIs to do the work on cheaper 5w synth's would mean it would thin out quicker than the 10w version of the same oil. I'll stick with good synth in a 5w-30 flavor. Unless of course, the engine makes noises (such as piston slap, etc), then it's time go thicker or change brands.
Originally posted by Patman: I want to turn this around the other way, since I'm really curious as to people's thoughts on this: What advantages do a 10w30 synthetic have over a 5w30 synthetic? I say none, since a good 5w30 synthetic will not thin out.
quote:Well that's true. But a 5W-30 is 60 cSt at 40 F and 10W-30 is 65 cSt at the same tmperature. The difference between 0W and 5W is too little to see on the graph. As far as the advantage of 10W-30 over 5W-30 probably about the same advantage 5W is in viscosity over the 10W at 40 F (Little to none
Originally posted by Patman:quote:Even if it only gets down to 40 or 50, the 5w30 could help.
Originally posted by Al: But in Texas there is simply no need for a 5W oil (IMHO)
![[Wink]](images/icons/wink.gif){kind=icon}
) But the 10W 30 would have little to no VI Improvers-and I just like that idea.
But in the end its all irrelevant to me as I am in the process of going exclusively to Schaeffer's 10W-30 Blend ![[LOL!]](/forums/graemlins/lol.gif)
This is interesting given the many recommendations in the UOA section that folks may want to try switching to M1 10w-30 over their 5w-30 to produce better wear numbers and lower oil consumption as it is 'more stable' and less prone to shearing. Am I missing something?
I am with you Nick778. We just don't need a 5w oil in this part of the country and I know 10w30 mobil 1 has highter HTHS specs.
Well Patman and I have view points 180 degrees from one another. I would say that with modern oils their is no need to keep 5W30 around any more if conventional oils are being discussed. With reguards to synthetic oils I see little improvment in real world conditions with 5W30 over 10W30. Unless you live in Alaska or Anartica I doubt that you could ever tell the difference in the two grades with out labratory equipment.
It has been my experince that 10W30 conventional oils hold up much better then 5W30 conventional oils. 10W30 synthetics also seem to be more consistent then their 5W30 brethren!
P.S. If you need some roofing tar just leave a chaep 5W30 dino oil in you truck for 7500 mile! Then scrape pan for tar! It can also be used to fill the craks in your drive way.
[ December 03, 2003, 08:09 PM: Message edited by: JohnBrowning ]
Patman
Staff member
If you look at all the Mobil 1 5w30 reports on here, you can see it doesn't thin out, same with Amsoil 5w30, Redline 5w30 and Schaeffer 5w30. Sure there are some other synthetic 5w30s we've seen which thin out (such as Royal Purple or some of the group 3 oils) but for the most part, the 5w30 version of the same oil is just as shear stable as that brands 10w30 is.
I do agree, dino 5w30 thins out, and for the most part so does a group 3 5w30. I think most well built 5w30s (and even some 0w30s) don't use all that much more VII than 10w30 (otherwise we would see them thinning out much more often) In a lot of cases these oils could just "naturally" be a 5w30 or 0w30, from having a very good base oil which just so happens to flow well enough to get the better cold cranking numbers.
Alright, here comes the bomb shell.
How about we get rid of 5W-30 and keep 0W-30 and 10W-30?
Pat, I respectfully disagree...I believe (UOAs show it) that M1 10W-30 is better than the 5W-30. Shear stability and a tad higher viscosity seems to be the reason.
So, I say for really cold climates below 0*F, use a quality 0W-30....any higher than 0*F use a quality 10W-30.
Rick
EDIT: I want to change my statement slighty. Why not just stick with a quality 0W-30 and skip the other two, regarless of weather?
[ December 03, 2003, 09:24 PM: Message edited by: Last_Z ]
Patman
Staff member
quote:This is exactly what I'm doing, not only in my own car, but my entire family's cars! (wife, mom and dad, and sister until she sold her car and moved west)
EDIT: I want to change my statement slighty. Why not just stick with a quality 0W-30 and skip the other two, regarless of weather?
The answer to this is brand specific ....
I'd have no problem recommending the Amsoil 0w-30 or Redline 5w-30 for year round use, even if you are the park ranger in Death Valley. However, I'd certainly recommend the Mobil 1, 10w-30 over their 0w-30/0w-40, since the latter two oils have shown a tendency to shear. The Mobil 1, 0w-30 is also consumed fairly rapidly in some high performance engines. The GC, 0w-30 seems to be holding up fine as well, so it would be a year round oil for all climates. I haven't seen enough data on other 0w-30's or 0w-40's to render an informed judgement.
I honestly don't see a big difference in going with 5w-30 over 10w-30 in the Amsoil product line, since those two oils are now using almost identical basestock blends. The latest VI on the 5w-30 is 174, vs 176 for the 10w-30. The CCS viscosities are also almost identical - 4990 Cp @ -30C for the 5w-30 and 3100 Cp @ -25C for the 10w-30. The rule of thumb for a PAO based synthetic is that the CCS viscosity will increase by a factor of 1.7, for every 5C drop in temperature. Do the math and you'll see what I mean ....
Tooslick
Dixie Synthetics
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