thinner is better

Joined
Aug 20, 2003
Messages
1,321
Location
ottawa
Hi According to everything i have read, 80% of engine wear occurs during startup.... if this were 100% true, then should everyone be using 0w oils in their engines, so that the oil will reach critical oil passages quicker ???????? im not sure if this has been discussed to death , i was just thinking of it this monring..... later nik [Smile]
 
Joined
May 12, 2003
Messages
7,798
Location
Oklahoma
Yes, it's been discussed in some detail. Two groups on here: thinner is better and thicker is better. Although I am a die-hard member of the later group, these UOA's are starting to make me re-think my own philosophy on that subject. In winter, no doubt, thinner is the winner. But, I want to see thinner oils with higher HTHS. I'm just not convinced yet that the thinner stuff can protect well when push comes to shove. My prime example, my boat. Mercruiser does not recommend anything below a 40 weight.
 
Joined
May 28, 2002
Messages
2,480
There is nothing to be gained with a 0 weight unless you are starting at -35C. Even at 0C (let alone 10, 20 or 30C) for example, there will be no difference whether you have a 0-30, a 5-30 or a 10-30. There is already oil present on all the surfaces for the couple of seconds req'd for oil pressure to reach normal at this temp. with these 3 viscosities.
 
Joined
May 12, 2003
Messages
7,798
Location
Oklahoma
Wow Yannis, some interesting stuff. Good read and excellent information. Kind of goes with my thinking that thicker is better for the bigger engines. Never actually understood why I felt that way, but now I see the light!!!! And also explains why HTHS is so important. Thinner oils can't handle high loads on the rod bearings. All those UOA's we've seen on V8's could be misleading. What we need is a UOA with 5W-20 on a big ol' V8 that has been worked, not just easy driving. [ April 06, 2004, 01:31 PM: Message edited by: Schmoe ]
 
Joined
Mar 2, 2003
Messages
1,096
Location
So Cal
schmoe, filling w/ RL 5w20 this weekend in my 5.4L f150. will take a while to get miles on it for a UOA but they will be hard miles going thru summer so should give us some info re holding up in hot weather conditions...
 
Joined
May 24, 2003
Messages
810
Location
Greece
quote:
Originally posted by zoomzoom: Schmoe, How come we are seeing low lead numbers form those ford V8's running M1 0W-20 and motorcraft 5W-20?
Maybe because they don't rev above 3000rpm?
 
Joined
Aug 6, 2003
Messages
451
Location
Bribie Island, Oz
quote:
Originally posted by Not the Autorx Frank: schmoe, filling w/ RL 5w20 this weekend in my 5.4L f150. will take a while to get miles on it for a UOA but they will be hard miles going thru summer so should give us some info re holding up in hot weather conditions...
Frank, You are a brave man. Let us know how the oil pressure holds up during a hot spell. The UOA should be interesting. cheers Dave [ April 06, 2004, 03:06 PM: Message edited by: DavoNF ]
 
Joined
Jun 26, 2003
Messages
643
Location
LA (Lower Alabama)
quote:
Originally posted by DavoNF: [QUOTE] Frank, You are a brave man. Let us know how the oil pressure holds up during a hot spell. The UOA should be interesting. cheers Dave
Unfortunately he will not know as the Fords do not have a oil pressure guage that has real pressure readings. They are more like an "idiot light" in that they read the same pressure no matter what the RPM's. Really crappy if you ask me.
 
Joined
Mar 2, 2003
Messages
1,096
Location
So Cal
Hes right I'll be able to tell if the pressure is on or off. Of course if it reads off then its prob too late to a darn thing about it I'll be droppin a few uoas though....
 
Joined
Jun 15, 2003
Messages
625
Location
Silver Spring, MD (USA)
We are sending a UOA to blackstone this coming weekend of a mazda6s (3.0 V6)... With over 2 hours of track time (VIR), and 48+ Autox runs on 0w-20 Mobil1 and a K&N HP2010 filter. You guys wanted track miles on the oil, you got it. Watch for the UOA report in a few weeks.
 
Joined
Jan 21, 2003
Messages
1,759
Location
Elizabeth City NC
Thanks yannis! A very interesting post. I have used 20w-50 Castrol GTX for years with little problem. This is what we used to race with back in the 70's-80's in SCCA racing. Also used was straight 40w Castrol R made from Castor Beans. My car recently overheated due to a bad radiator. It survied just fine and I am not so sure it would have with 10w-30. 30weight is the minimum I would use in any car. In the Philippines almost no one uses 30 weight and the 20w-50 is kind of the normal viscosity. It gets awful hot over there. I would like to see what would happen if you drove a car 10 miles with no water on 0w-20 Mobil 1. We get two old beaters one with 20w-50 and one with 0w-20. No water and see which will seze up first. [crushedcar]
 
Joined
Jul 29, 2003
Messages
960
Location
Kyiv, Ukraine
quote:
Originally posted by Schmoe: In winter, no doubt, thinner is the winner.
Not always. According to my winter experience the oil temperature in winter was quite often 10-15 C higher then in summer and at such moments I was happy to have Castrol 10W-60. Think the only explanation is a lot of snow-drifts to be get over and thermostat becoming crazy: in winter the coolant goes through a small circle most of the time, but when the car is a half in snow, the temperature may jump very quickly, so the termostat switch on does not help to cool the engine in the right moment. This can be repeated several times before the speed will not be stabilized.
 
Joined
Oct 18, 2003
Messages
805
Location
Earth
If I had the choice to run German Castrol 0w-30 or Mobil 1 10w-30 during the summertime, I'd pick GC due to its thicker viscosity at operating temp. Plus, even if the summertime temps reach 40ºC or 104ºF outside, GC is still going to be thicker than M1 when you start your car. M1 10w-30 = 62.0 [email protected]º C GC 0w-30 = 68.5 [email protected]º C M1 10w-30 = 10.0 [email protected]º C GC 0w-30 = 12.1 [email protected]º C
 
Joined
Jun 15, 2003
Messages
625
Location
Silver Spring, MD (USA)
Temp of the day at VIR was 75F I believe. No oil temp gauge in the 6 that drove on it. Tires/brake pads/brake fluid needed replacement after the day though [Smile] . We'll see how the oil looks when the UOA comes in. According to some guys, the engine should be ruined and non functional.
 
Joined
Mar 5, 2004
Messages
58
Location
Indy
[QUOTE]What we need is a UOA with 5W-20 on a big ol' V8 that has been worked, not just easy driving. There is a UOA for MC 5W-20 in a V10 pulling a trailer through the mountains. The UOA was very good. I believe the Ford V-10 and 5.4 V8 both have a longer stroke than the 4.6 V8. According to the article, the 4.6 should be easier on the oil.
 
Joined
Feb 13, 2003
Messages
1,357
Location
California, USA
quote:
Originally posted by nicholas: Hi According to everything i have read, 80% of engine wear occurs during startup....
Where has this been documented? It seems like the "thinner is better" folks are concentrated in Canada, Colorado and similar cold-winter climates, so it would seem a reasonable idea to them. Those from Australia, Texas, etc. are more likely to believe that "thicker is better". Again, no surprise. I have UOA's with 15W-40 that show extremely low wear metals, but a typical winter low temperature here is +40F. Even in mountain resort areas, +17F is the lowest temperature we saw this year. My problem with 0W and 5W oils is that the base stocks have to be of lower molecular weight, even with the synthetics, and VII's added to get to 30 or 40 at 100C. As was explained in detail in another post, this is less stable than starting with a thicker base oil. As far as race cars using different weights, thick or thin, that is irrelevent to street vehicles because a race engine is intended to produce maximum output and last only to the finish line.
 
Top