OK, please bear with me on this. It seems to me that if someone asks here for advice on what oil to use, the standard answer is, "use whatever oil the manufacturer recommends," or some variation of that. However, if someone says, hey, I've got an old 283 Chevy, or 460 Ford or something along those lines, the common recommendation is 15w40 HDEO. Am I wrong on this? What am I missing?
BITOG viscosity recommendations question
- Thread starter Stelth
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An owners manual written in the sixties is obsolete with regard to today's oil choices.
I would still put in the same high temperature viscosity grade that the OEM recommended, but I wouldn't feel bad about putting in a multigrade if they didn't recommend one. For instance, if the OEM recommended a monograde 30 from 32-120F, and 10w30 from 0 to 60 degrees, I would run a 10w30 from 0 to 120F.
If your old engines have high miles and burn a lot of oil, and originally specified 30-weight, then going to 40-weight may slow down consumption and improve oil pressure.
BITOG'ers tend to specify 15w40 HDEO's for the higher zddp that diesel oils tend to have and because many old engines require 40-weights. Not to mention that HDEO's are readily available and low cost.
For most engines from the Golden Age of Musclecars, I recommend Valvoline VR1 conventional 10w30 or a blend of 10w30 and 20w50. I'm currently running the 10w30 in my 1972 GMC pickup.
If your old engines have high miles and burn a lot of oil, and originally specified 30-weight, then going to 40-weight may slow down consumption and improve oil pressure.
BITOG'ers tend to specify 15w40 HDEO's for the higher zddp that diesel oils tend to have and because many old engines require 40-weights. Not to mention that HDEO's are readily available and low cost.
For most engines from the Golden Age of Musclecars, I recommend Valvoline VR1 conventional 10w30 or a blend of 10w30 and 20w50. I'm currently running the 10w30 in my 1972 GMC pickup.
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My buddy broke in his 73 Camro running a streetable 383 SBC using Dexron ATF. Ran it a month without clinking or clanking or spinning a bearing or toasting rings. Could one extrapolate that she would run fine and snappy on redline SAE20W20 or Joe Gibbs SAE10 qualifiying lube (Instead of M1 TDT).
I say Forget the overrated horsepower robbing 15w40 Chevron slop.
I say Forget the overrated horsepower robbing 15w40 Chevron slop.
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I believe if they had the oils then that we have now, they would have recommended using them. If they had a super good 30 or 20, they'd have recommended it, and you know for sure the racing crowd would be using it. Not only does the thicker oil Rob power, your getting less flow, sure a thicker oil can handle more heat, and it will have to because your engine oil temps may go up. I used to preach against thin oils, but I always felt stupid without evidence of one single engine that wore out due to a thin oil. Now after being convinced by someone who has more education in the way fluids(including motor oil) behave than I, I'm running a 20, plan on oil analysis @ 10k(amsoil SS oil&filter) so far very satisfied. One thing they probably thought about was shearing. Recommending to start with a 40 because it would shear down to a 30 relatively quick, those old spec oil' s probably weren't anything like today's oil in the shear stability department.
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As others have pointed out there really isn't a case for using the unduly heavy low VI 15w40 grade.
A HDEO 10W-30 is just as cheap to buy, still heavier than most 0W/5W-40 PCMOs due do it's low VI plus it has the higher ZDDP levels many want.
A HDEO 10W-30 is just as cheap to buy, still heavier than most 0W/5W-40 PCMOs due do it's low VI plus it has the higher ZDDP levels many want.
Originally Posted By: Stelth
OK, please bear with me on this. It seems to me that if someone asks here for advice on what oil to use, the standard answer is, "use whatever oil the manufacturer recommends," or some variation of that. However, if someone says, hey, I've got an old 283 Chevy, or 460 Ford or something along those lines, the common recommendation is 15w40 HDEO. Am I wrong on this? What am I missing?
you want to have some fun, look at what our friends from OZ/ SouthEast Asia use.....
OK, please bear with me on this. It seems to me that if someone asks here for advice on what oil to use, the standard answer is, "use whatever oil the manufacturer recommends," or some variation of that. However, if someone says, hey, I've got an old 283 Chevy, or 460 Ford or something along those lines, the common recommendation is 15w40 HDEO. Am I wrong on this? What am I missing?
you want to have some fun, look at what our friends from OZ/ SouthEast Asia use.....
Thats why I am not sweating mixing 5-30 with sae40 in my old Chevy truck, in hot TX. The final blend will be a "36 wt." Truck probably won't notice.
Originally Posted By: gfh77665
Thats why I am not sweating mixing 5-30 with sae40 in my old Chevy truck, in hot TX. The final blend will be a "36 wt." Truck probably won't notice.
No the blend will be a heavier 30wt or a lighter 40wt.
Thats why I am not sweating mixing 5-30 with sae40 in my old Chevy truck, in hot TX. The final blend will be a "36 wt." Truck probably won't notice.
No the blend will be a heavier 30wt or a lighter 40wt.
Originally Posted By: pandus13
Originally Posted By: Stelth
OK, please bear with me on this. It seems to me that if someone asks here for advice on what oil to use, the standard answer is, "use whatever oil the manufacturer recommends," or some variation of that. However, if someone says, hey, I've got an old 283 Chevy, or 460 Ford or something along those lines, the common recommendation is 15w40 HDEO. Am I wrong on this? What am I missing?
you want to have some fun, look at what our friends from OZ/ SouthEast Asia use.....
Yes but as everybody knows the laws of physics are different in that part of the world, or at least that's what they would have you believe.
Originally Posted By: Stelth
OK, please bear with me on this. It seems to me that if someone asks here for advice on what oil to use, the standard answer is, "use whatever oil the manufacturer recommends," or some variation of that. However, if someone says, hey, I've got an old 283 Chevy, or 460 Ford or something along those lines, the common recommendation is 15w40 HDEO. Am I wrong on this? What am I missing?
you want to have some fun, look at what our friends from OZ/ SouthEast Asia use.....
Yes but as everybody knows the laws of physics are different in that part of the world, or at least that's what they would have you believe.
Originally Posted By: Shannow
No, the laws of physics function just fine, in spite of what people "feel" or "believe" when discussing science.
You're right, it's cultural which has nothing to do with science.
No, the laws of physics function just fine, in spite of what people "feel" or "believe" when discussing science.
You're right, it's cultural which has nothing to do with science.
Originally Posted By: CATERHAM
Originally Posted By: gfh77665
Thats why I am not sweating mixing 5-30 with sae40 in my old Chevy truck, in hot TX. The final blend will be a "36 wt." Truck probably won't notice.
No the blend will be a heavier 30wt or a lighter 40wt.
Yes I know... I know... Thats why I put "36 wt." in quotes. I know "36" is not an official viscosity, but it gets the message across. I thought the quotes would cover that.
BTW, there IS an official 16wt. now, just sayin.
Originally Posted By: gfh77665
Thats why I am not sweating mixing 5-30 with sae40 in my old Chevy truck, in hot TX. The final blend will be a "36 wt." Truck probably won't notice.
No the blend will be a heavier 30wt or a lighter 40wt.
Yes I know... I know... Thats why I put "36 wt." in quotes. I know "36" is not an official viscosity, but it gets the message across. I thought the quotes would cover that.
BTW, there IS an official 16wt. now, just sayin.
Originally Posted By: Shannow
No, the laws of physics function just fine, in spite of what people "feel" or "believe" when discussing science.
I always thought a thin oil would jump from the oil pan up to the valve covers down there. A thick oil will keep the pump primed.
No, the laws of physics function just fine, in spite of what people "feel" or "believe" when discussing science.
I always thought a thin oil would jump from the oil pan up to the valve covers down there. A thick oil will keep the pump primed.
Originally Posted By: Garak
Originally Posted By: Shannow
No, the laws of physics function just fine, in spite of what people "feel" or "believe" when discussing science.
I always thought a thin oil would jump from the oil pan up to the valve covers down there. A thick oil will keep the pump primed.
I thought there must be a good explanation for it and that's about the best I've heard so far!
Originally Posted By: Shannow
No, the laws of physics function just fine, in spite of what people "feel" or "believe" when discussing science.
I always thought a thin oil would jump from the oil pan up to the valve covers down there. A thick oil will keep the pump primed.
I thought there must be a good explanation for it and that's about the best I've heard so far!
Are our friends from OZ/ SouthEast Asia having engine longevity issues with the 20-50 they use so often? Just wondering if there is a real difference.
Originally Posted By: gfh77665
Are our friends from OZ/ SouthEast Asia having engine longevity issues with the 20-50 they use so often? Just wondering if there is a real difference.
I doubt it. It's not an engine longevity issue just one of efficiency. Engines, particularly in a hot climate are pretty tolerant of whatever grade oil you run in them.
Are our friends from OZ/ SouthEast Asia having engine longevity issues with the 20-50 they use so often? Just wondering if there is a real difference.
I doubt it. It's not an engine longevity issue just one of efficiency. Engines, particularly in a hot climate are pretty tolerant of whatever grade oil you run in them.
Originally Posted By: CATERHAM
Originally Posted By: Shannow
No, the laws of physics function just fine, in spite of what people "feel" or "believe" when discussing science.
You're right, it's cultural which has nothing to do with science.
Yes, cultural. "Thicker oils provide a thicker oil wedge in bearings", is only true if you say it with an Australian accent.
Ed
Originally Posted By: Shannow
No, the laws of physics function just fine, in spite of what people "feel" or "believe" when discussing science.
You're right, it's cultural which has nothing to do with science.
Yes, cultural. "Thicker oils provide a thicker oil wedge in bearings", is only true if you say it with an Australian accent.
Ed
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