CAFE has Little to do with Motor Oil Viscosity Use

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Originally Posted By: Garak
Question, then. Why are you using 15w-50 then,


Because it`s the only 50 weight synthetic that I can buy which isn`t rediculously expensive. It`s only $4.99 a quart :^) Plus I`m lucky enough to live in Texas,the greatest place on earth!
 
Originally Posted By: aquariuscsm
Originally Posted By: mechtech2
I don`t understand the easier starting thing. My car starts the exact same whether I`m using 20W50 or 5W30.

"Startup wear" etc is all liberal government CAFE propaganda. It simply doesn`t exist.]
[From Dave 1251]

1. Your car does not start the exact same with those 2 highly disparate oils. Neither does anyone else's. Why say such nonsense?
2. There is no connection to CAFE and start up wear 'propaganda'.
Before CAFE existed, start up and cold engine oil problems were well noted. Decades before. Oil flow is good for engines, and start up and cold running can have very poor oil flow with thick oils. Everybody knew that.


I`ve owned my Z for a bit over 8 years and have tried everything from 5W30 (which was stupid because my owner`s manual and fsm say not to) to 20W50. Engine spins the exact same speed when I engage the starter. Unless a car has a weenie little starter or a low quality battery,I just don`t see how an oil would change the starting speed. I`ve had the oil cap off on cold morning startups with 50 weight oil and it`s bathing the camshafts in a nice thick coat of oil as soon as the starter moves the engine.
21.gif
I absolutely LOVE those posts saying anything other than W20 oils can`t reach those pesky "nooks and crannies" of the engine! I`m like,huh?????????


You do not HAVE cold starts in south Texas! This last winter was mild...even so, it was 25-30 degrees or colder almost every morning. We had about a week of 0-10 degree mornings...the previous winter, it was 25 degrees or colder almost every morning for probably three months.

Bring that car up here in February, see how slow it cranks with 20W-50 in the crankcase!
 
Originally Posted By: Jarlaxle
Originally Posted By: aquariuscsm
Originally Posted By: mechtech2
I don`t understand the easier starting thing. My car starts the exact same whether I`m using 20W50 or 5W30.

"Startup wear" etc is all liberal government CAFE propaganda. It simply doesn`t exist.]
[From Dave 1251]

1. Your car does not start the exact same with those 2 highly disparate oils. Neither does anyone else's. Why say such nonsense?
2. There is no connection to CAFE and start up wear 'propaganda'.
Before CAFE existed, start up and cold engine oil problems were well noted. Decades before. Oil flow is good for engines, and start up and cold running can have very poor oil flow with thick oils. Everybody knew that.


I`ve owned my Z for a bit over 8 years and have tried everything from 5W30 (which was stupid because my owner`s manual and fsm say not to) to 20W50. Engine spins the exact same speed when I engage the starter. Unless a car has a weenie little starter or a low quality battery,I just don`t see how an oil would change the starting speed. I`ve had the oil cap off on cold morning startups with 50 weight oil and it`s bathing the camshafts in a nice thick coat of oil as soon as the starter moves the engine.
21.gif
I absolutely LOVE those posts saying anything other than W20 oils can`t reach those pesky "nooks and crannies" of the engine! I`m like,huh?????????


You do not HAVE cold starts in south Texas! This last winter was mild...even so, it was 25-30 degrees or colder almost every morning. We had about a week of 0-10 degree mornings...the previous winter, it was 25 degrees or colder almost every morning for probably three months.

Bring that car up here in February, see how slow it cranks with 20W-50 in the crankcase!


Haha you got that one right! We wore shorts and t`s all winter last year :^)
 
Originally Posted By: KrisZ
Good discussion so far, but I see no compelling arguments that CAFE has little to do with oil viscosity use.

Either way, I trust car manufacturers that whatever oil viscosity they choose will provide good service life.


I agree. Since roller camshafts, you can go lower vis and get away with much lower ZDP levels.
 
Originally Posted By: aquariuscsm
Because it`s the only 50 weight synthetic that I can buy which isn`t rediculously expensive. It`s only $4.99 a quart :^)


Well, time to take one for the team, then. RP 50 grade comes in sizes up to 5 gallons, is SJ rated (for plenty of zinc), and has a wonderful VI of 113. Let us know if it turns over any better or worse than, say, a 0w-30 or 0w-40.

I know the limitations of kinematic viscosity, but that's all I've got handy for RP. KV at 40 C of the straight 50 is 182.0. For their 0w-20, it's 42.58, with a VI of 177. You may not notice a difference, but there certainly is. Automakers went to multigrades decades ago for a reason.
 
I went from straight 30 to 25W-70 one winter, down to -5C, and I can tell you for sure that the 2.0L J-car cranked more sluggishly...lots more.

Yes, oil was seen dribbling off the cams as it cranked.

Yes, I lost 10% of it's fuel economy.
 
Shannow, I think my dad would have beat me if I tried anything that thick. It just about happened when when I put straight 30 in an application that even allowed it. Fortunately, I was closer to the owner's manual than he was to the belt.
wink.gif
He was still very unimpressed.
 
Originally Posted By: Garak
Originally Posted By: aquariuscsm
Because it`s the only 50 weight synthetic that I can buy which isn`t rediculously expensive. It`s only $4.99 a quart :^)


Well, time to take one for the team, then. RP 50 grade comes in sizes up to 5 gallons, is SJ rated (for plenty of zinc), and has a wonderful VI of 113. Let us know if it turns over any better or worse than, say, a 0w-30 or 0w-40.

I know the limitations of kinematic viscosity, but that's all I've got handy for RP. KV at 40 C of the straight 50 is 182.0. For their 0w-20, it's 42.58, with a VI of 177. You may not notice a difference, but there certainly is. Automakers went to multigrades decades ago for a reason.


I`d actually thought about using RP mono 40 during the winter and RP mono 50 during the summer at one time. But at $10 per quart and no more Synerlec,my RP days are over :^( I had an absolute perfect uoa on RP Synerlec 20W50 awhile back. All city driving mostly (I work about 5 miles from my house) with a few races and a few 3 hour hwy runs with the cruise set on 85mph.

RP`s multigrades also looked better on paper spec wise over their multigrades. 20W50 had a higher flashpoint over their mono 50 for example.
 
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Originally Posted By: Shannow
Garak, it was basically a BITOG dare, to prove that 25W-70 wouldn't explode an engine in winter...it didn't like it.

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=36800


Mmmmm, vintage BITOG. It's interesting to read the old stuff.

But I'm still a little bemused by the Australian cultural preference for thick oils. I worked with Orbital Engineering a couple of years back on an engine project, and when it came down to selecting oil for our testing in America, the oil spec was for an SJ-rated 15w40. This is an oil grade I don't ever remember seeing in the US. The Australians seemed to think that anything below 40-weight was only marginally suitable for door hinges. I spent days trying to find the stuff in North America, and came up empty. I ended up buying Amalie 20w50 and 10w30 that was SJ-rated, and did a blend to make 15?w40.
 
aquariuscsm: Why do you keep saying RP's Synerlec is gone? It's in their XPR and HPS oils. The HPS looks to be largely the same oil as their regular line was before the API licensed oils appeared.
 
To those claiming that oil weight doesn't make a difference in winter starts you have obviously never poured a quart of oil in the middle of a northern winter. At 20 or 30 below zero a normal 5W-30 that has sat out all night is pretty darn thick, and something like a 10W-40 takes awhile to get moving. You stick the bottle in the oil hole and then go inside and drink a hot cup of coffee while its emptying into your engine. Here's an old BITOG post on this subject. Oil Pour Test. Back in the day ('60s), when we all ran thicker oil, I can remember mornings where the engine wouldn't turn over until we heated up the oil pan for awhile. Even around zero you can hear and feel a significant difference in starting ability using 5W-30, which is my usual fill for a couple of cars.
 
Originally Posted By: A_Harman
Originally Posted By: Shannow
Garak, it was basically a BITOG dare, to prove that 25W-70 wouldn't explode an engine in winter...it didn't like it.

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=36800


Mmmmm, vintage BITOG. It's interesting to read the old stuff.

But I'm still a little bemused by the Australian cultural preference for thick oils. I worked with Orbital Engineering a couple of years back on an engine project, and when it came down to selecting oil for our testing in America, the oil spec was for an SJ-rated 15w40. This is an oil grade I don't ever remember seeing in the US. The Australians seemed to think that anything below 40-weight was only marginally suitable for door hinges. I spent days trying to find the stuff in North America, and came up empty. I ended up buying Amalie 20w50 and 10w30 that was SJ-rated, and did a blend to make 15?w40.


Whaaaaaaaaaaaat?! 15W-40 is dirt-common, available at any auto part store, Wal-Mart, or truck stop.
 
A 15w40 that is primarily rated for gasoline engines is very rare. All the 15w40's that you see on the shelf are primarily rated for diesels, and secondarily for gasoline engines. The CJ4/SM stamp really does mean primarily for diesels. I was looking for a stamp that had SJ as the primary, such as SJ/CF.
 
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Quote:
Honda is the fifth-largest marketer of vehicles in the United States, second-largest in Japan, and the largest manufacturer of engines in the world - more than 10 million per year. Seventy percent of its 2001 model year U.S. fleet, including all Civics and Accords, are being sold with 5w-20 oil in the crankcase along with a recommendation in the owner's manual to use 5w-20 for all oil changes. This will move to 90 percent within a few years.

Honda's reasons for moving to 5w-20 parallels Ford's but without the CAFE incentive. As Honda's Principle Chemist Jeff Jetter puts it, "We're so far ahead of the mpg curve that CAFE was not an issue. We meet EPA requirements easily. But we're a very 'green' company and believe that the fuel economy improvement provided by 5w-20 is important."

Jetter adds, "We've used low-viscosity oil in the Japan market for a number of years and our testing indicates that it's acceptable here for Civics back to 1996 and Accords back to 1998. We're satisfied with backward compatibility of 5w20 in our earlier models. Durability is not an issue, either. If it were, we wouldn't recommend 5w-20."
 
Originally Posted By: A_Harman
A 15w40 that is primarily rated for gasoline engines is very rare. All the 15w40's that you see on the shelf are primarily rated for diesels, and secondarily for gasoline engines. The CJ4/SM stamp really does mean primarily for diesels. I was looking for a stamp that had SJ as the primary, such as SJ/CF.


Very very common down here. Valvoline make engine armour, nextgen, and all sorts...as do everyone else.
 
Originally Posted By: Jim Allen
aquariuscsm: Why do you keep saying RP's Synerlec is gone? It's in their XPR and HPS oils. The HPS looks to be largely the same oil as their regular line was before the API licensed oils appeared.


Guess I should`ve said the otc stuff. I used to be able to get it for $6 a quart. HPS is around $12+shipping,no way for me!
 
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