Again, not the point of this thread.quote:
Originally posted by Shannow:
what about if it states 5W-30 over there, and 10W-50 here ?
Why wouldn't you want an oil with a better add pack? Just because its a little thicker? The extra viscosity doesn't make that much difference!quote:
Originally posted by BlazerLT:
Tell them to go to a 15w40 just because of the 15w40 having "supposedly" a better additive pack is just plain wrong.
OK, can you post another thread that is actually defining the point of the thread ?quote:
Originally posted by BlazerLT:
Again, not the point of this thread.quote:
Originally posted by Shannow:
what about if it states 5W-30 over there, and 10W-50 here ?
If the vast majority of engine wear occurs in the first few seconds of a cold start then the optimal viscosity would be the thinest cold viscosity one could find, probably 0w or 5w depending on the temp (5w is thinner than 0w until maybe -20F).quote:
Originally posted by Shannow:
good point.
your first 3 seconds are vastly different to my 3 seconds.
There's the point at which the engine is "dry" (BTW, most (all?) of the engines I've pulled apart still had a film of oil on all wearing surfaces) and the oil has to get to all lubtricated points.
Then it then takes a while for the antiwear additives to kick in, as they need some heat.
So what do you feel is the optimum viscosity ?
If economics were the objective then everyone would use the "on sale" dino oil of the appropriate viscosity and a $2 oil filter for a maybe $5 oil change every 3,000 miles. Engines would outlast the body and all would save $$. Total cost of oil changes for 300,000 miles would be $500.quote:
Originally posted by pitzel:
I think you have to look at how engines are turning up when cars are sent to the scrapper or are being sold off after a long life of use.
The junkyards here are filled with two types of cars: either a) cars that haven't received much in terms of maintenance and have messed up engines and other components, or b) cars that have perfectly good engines but are complete wrecks.
In essence, what this information leads me to believe is that properly maintained cars are not being sent to the scrapper unless they are also wrecks. In which case, their engines are perfectly fine.
What can be deduced from this is that maybe there is far too much emphasis on reducing engine wear since most engines in most cars driven an average number of miles can outlast the body and other components.
Meanwhile savings from fuel are tangible and can be measured. A 2% improvement in fuel consumption over the period of 300k miles at 30mpg is 210 gallons of fuel or roughly $420 at $2/gallon. Put a 10% discount rate on those figures, 3% inflation in oil and the general economy, and that is a current savings of $672.
As anyone here can tell you, $672 goes a long, long ways towards buying a 15-year-old vehicle, or a reasonable specimen of an engine out of a 15-year old car that could be swapped in.
I don't know about you, but I'd rather be sending a totally worn out and rusted through car to the shredder and have $672 in my pocket rather than send the same vehicle with a slightly less worn engine to the wrecker without that $672 in my pocket.
Keeping the wear to an absolute minimum in an engine does absolutely nothing if the other systems in the car are functionally or technically obsolete -- for example, a 1981 GM I own that still drives like brand new, but was never built to be powerful enough to cruise at modern freeway speeds. And the evidence isn't exactly very strong either that contemporary 5W-20 oils promote accelerated wear in the engines they are spec'ed for.
quote:
OK, can you post another thread that is actually defining the point of the thread ?
Bryan,quote:
Originally posted by Bryanccfshr:
On my oil scavenger hunt through various autozones I here the darndest things.
It is hardwired in to many peoples heads that thicker is better. And they absolutely fear low numbers. It goes with the supersized, bigger is better, if a little is good alot must be great, Attitudes.
SNIP
While this is a good financial analysis, you're assuming the 2% improvement in fuel consumption is guaranteed for every engine, in every climate, under all driving conditions and average trip length. I've read scientific papers that show that this isn't always the case, and my personal experience corroborates this. YMMV.quote:
Originally posted by pitzel:
Meanwhile savings from fuel are tangible and can be measured. A 2% improvement in fuel consumption over the period of 300k miles at 30mpg is 210 gallons of fuel or roughly $420 at $2/gallon. Put a 10% discount rate on those figures, 3% inflation in oil and the general economy, and that is a current savings of $672.
Good point, but 2% isn't that unrealistic if you compare a 5W-20 to a 15W-40 HDEO. Even if the figure is 1%, half of that, $300 saved per vehicle multiplied by the 200 hundred million vehicles on the road is 'only' $60 billion.quote:
Originally posted by 427Z06:
[/QB]While this is a good financial analysis, you're assuming the 2% improvement in fuel consumption is guaranteed for every engine, in every climate, under all driving conditions and average trip length. I've read scientific papers that show that this isn't always the case, and my personal experience corroborates this. YMMV. [/QB]
All true. My GM manual specifically states not to use 20W-50 period. They know that these cars will try to start no matter what and some idiot in Antarctica will break the oil pump and claim warranty.quote:
Originally posted by Dr. T:
Blazer, you must remember several facts:
N.A. owner's have been dummied-down into thinking "use 5-30" for everything everytime every temperature. Now it's 5-20.
Sadly, the tried-and-true recommendation of viscosity based on temperature has been abandoned. But, some owner's have reported this on a continent to continent variation. Others note a Euro to US difference in the same engine. Yet others (like myself), have ALL grades listed in my manual...eg. 5-20 up to 20-50. Why? Because they all work. But when does one work better?
I will clarify it:
A dino 15-40 is BETTER than a dino 5-20 in ALL engines when it is 30-40 C outside (eg. Arizona, Texas, etc).
Conversely, a dino 5-20 is BETTER than a dino 20-50 in ALL engines when it is -30C outside eg. Canada
Tom,quote:
Originally posted by TomJones76:
Bryan,quote:
Originally posted by Bryanccfshr:
On my oil scavenger hunt through various autozones I here the darndest things.
It is hardwired in to many peoples heads that thicker is better. And they absolutely fear low numbers. It goes with the supersized, bigger is better, if a little is good alot must be great, Attitudes.
SNIP
I know exactly what you mean. You know, the SAE numbers are based on what amounts to a completely arbitrary metric, albeit one that had some meaning in one particular engine around the time of the first World War.
What would our discussion on this topic be like if the SAE scale had been inverted?
What if rather than (originally) measuring time to flow through an arbitrary engine, the number was based on "Speed of Flow" or "Slipperiness Index" ?
I wonder if we'd still have that attitude.
Good luck trying to convince people who drive a LS1/LS6/LS2/LS7 hard without an oil cooler in FL, GA, AL, MS, LA, TX, OK, AZ, NM, NV during the summer months to use an inexpensive dino 5w20 instead of a 15W-40 HDEO to possibly gain 1% better fuel economy.quote:
Originally posted by pitzel:
Good point, but 2% isn't that unrealistic if you compare a 5W-20 to a 15W-40 HDEO.
Talk to Patman.quote:
Originally posted by 427Z06:
Good luck trying to convince people who drive a LS1/LS6/LS2/LS7 hard without an oil cooler in FL, GA, AL, MS, LA, TX, OK, AZ, NM, NV during the summer months to use an inexpensive dino 5w20 instead of a 15W-40 HDEO to possibly gain 1% better fuel economy.quote:
Originally posted by pitzel:
Good point, but 2% isn't that unrealistic if you compare a 5W-20 to a 15W-40 HDEO.