Dealer using 5W20 in Phoenix AZ!!!!

[M1Ark]

Originally Posted By: BuickGN


Talk about backwards. So since you're in a very hot climate which thins the oil, they recommend a thinner oil to protect from the thinning? I would find another dealer. That's crazy.

Maybe in the winter you can run a straight 60wt too.


I laughed at them when they said it.

 

[Bryanccfshr]

Originally Posted By: M1Ark
My only concern is most of my driving is 80-85 in 115-117f weather. I guess the thermostat will still keep the oil and coolant at the set temperature.


All 120 degrees does is reduce the temperature differential, in the scheme of things it is not that hot compared to the oils temperature so convection and radiation are constantly drawing heat from the oil even over hot asphalt the oil is hotter and throwing heat out to the pavement not the other way around. Heat goes to in the direction of cool.

80-85 mmph is pretty good and easy driving , your engine will last a very along time if you do this often.

 

[panthermike]

I would use 5w30 or 10w30. I don't believe in running 5w20 if it's not spec'd.

 

[andrewg]

Can't believe so many are of the opinion that there own judgement is a replacement for the manufacturer specification.

 

[Bryanccfshr]

Do you understand the practical differences between these very similar multiviscosity oils? Does the ILSAC rating that they all meet require more stringent wear protection for one grade over the other?...tell me what grades have more stringent requirements outside of viscosity which again is only a nominal difference.

 

[BuickGN]

Originally Posted By: Bryanccfshr
Originally Posted By: M1Ark
My only concern is most of my driving is 80-85 in 115-117f weather. I guess the thermostat will still keep the oil and coolant at the set temperature.


All 120 degrees does is reduce the temperature differential, in the scheme of things it is not that hot compared to the oils temperature so convection and radiation are constantly drawing heat from the oil even over hot asphalt the oil is hotter and throwing heat out to the pavement not the other way around. Heat goes to in the direction of cool.

80-85 mmph is pretty good and easy driving , your engine will last a very along time if you do this often.


In the GN (since it's the only car I monitor oil temps) I see roughly 3 degrees increase in oil temps for every 10 degrees in ambient. Ambient temps do make a difference. Think about the heat radiating from the asphalt too. I've lived in Vegas and Mesa/Phoenix and I've drained my oil on a very hot engine and the straight 30wt I was running looks thinner than water at 200+F.

 

[M1Ark]

I agree with the temperature differential except your argument is a little off. Rate of heat transfer is directly proportional to the difference in temperature. This means if outside air temperature is 20f warmer then the oil temp has to go up to raise the differential temperature to establish the same heat transfer rate.

Sorry... the engineer in me came out.

 

[Colt45ws]

Okay, out of curiosity, let say an coolant temperature of 93C and a oil temp of 85C. Lets take a popular conventional 10W30 with a viscosity of 10.53cSt@100C and a VI of 135. This would have a approximate viscosity of 15.15cSt@85C. This same brand in 5W20 has a viscosity of 8.4cSt@100C and a VI of 150. Approximate viscosity at the specified temperature would be 11.7cSt. While this is a math derived number, the difference is a bit more than at 100C. Admittedly, it probably does not make much of a difference, yes.

 

[BuickGN]

Originally Posted By: Bryanccfshr
Do you understand the practical differences between these very similar multiviscosity oils? Does the ILSAC rating that they all meet require more stringent wear protection for one grade over the other?...tell me what grades have more stringent requirements outside of viscosity which again is only a nominal difference.


Then why don't they spec a 20wt from the factory for slightly better fuel economy and all that other stuff the thin guys love to talk about?

What about the HTHS difference. I would venture a guess that since they spec'd a 10w-30 and not a 5w-30, there may be a higher HTHS requirement for that engine.

That nominal difference could be the difference between virtually no wear and metal to metal contact on a 115 degree day blazing down the freeway. A nice hour cruise down the freeway at 80mph produces much higher oil temps than stop and go traffic.

 

[Bryanccfshr]

You are correct, the decrease in temperature differential makes the heat transfer less efficeint, it is still there nonethe less.
I doubt the OP's engine and load at 85 is near BGN's GN at the same conditions. THe GN is under boost and that has to be taken into account with his GN testimonials . The turbo is a huge heat source.

 

[Peted]

Originally Posted By: Bryanccfshr
What difference is their between an energy conserving 10w30 and a 5w20? 2 cst? .3 on the HTHS scale?


1 more mile per gallon.

Originally Posted By: BuickGN
I know you're new to this board but you'll find that there are people that will recommend a 20wt for anything and everything regardless of ambient temps, manufacturer's recommendation, and driving style.


Quote of the day.

 

[Bryanccfshr]

Originally Posted By: BuickGN
Originally Posted By: Bryanccfshr
Do you understand the practical differences between these very similar multiviscosity oils? Does the ILSAC rating that they all meet require more stringent wear protection for one grade over the other?...tell me what grades have more stringent requirements outside of viscosity which again is only a nominal difference.


Then why don't they spec a 20wt from the factory for slightly better fuel economy and all that other stuff the thin guys love to talk about?

What about the HTHS difference. I would venture a guess that since they spec'd a 10w-30 and not a 5w-30, there may be a higher HTHS requirement for that engine.



There is no more stringent HTHS requirement for a 10w30 over a 5w30 they both require a minimum 2.9 most the time the HTHS is the same between these grades. a 2.9-3.1 much higher and they cannot pass the fuel economy requirements. The minimum for a 5w20 is 2.6. Again this number varies by the particular blends ability to meet the fuel economy requirement. SOme are up to 2.9 some ar edown near 2.6 the rough mean difference is .3 between any. Are you going to say you trust production tolerance to garantee .3 differnce if your engine really needs .3 hths difference for its durability?

 

[M1Ark]

I'm not seeing the 1 mpg

 

[BuickGN]

Originally Posted By: Bryanccfshr
You are correct, the decrease in temperature differential makes the heat transfer less efficeint, it is still there nonethe less.
I doubt the OP's engine and load at 85 is near BGN's GN at the same conditions. THe GN is under boost and that has to be taken into account with his GN testimonials . The turbo is a huge heat source.


The GN is under roughly 10" of vacuum cruising steady state down the freeway. In fact it never sees boost during normal driving.

The turbo isn't a huge source of heat. Oil flows through the center section very fast and it carries some heat away but it's minor. Turbo engines only run hotter when in boost. Cruise is the same as any normal car, unless it requires boost to cruise down the freeway.

Load would be the same regardless of what engine is in the car. It is pushing something with the aerodynamics of a brick through the air but it's still a pretty normal example.

 

[BuickGN]

Originally Posted By: Bryanccfshr
Originally Posted By: BuickGN
Originally Posted By: Bryanccfshr
Do you understand the practical differences between these very similar multiviscosity oils? Does the ILSAC rating that they all meet require more stringent wear protection for one grade over the other?...tell me what grades have more stringent requirements outside of viscosity which again is only a nominal difference.


Then why don't they spec a 20wt from the factory for slightly better fuel economy and all that other stuff the thin guys love to talk about?

What about the HTHS difference. I would venture a guess that since they spec'd a 10w-30 and not a 5w-30, there may be a higher HTHS requirement for that engine.



There is no more stringent HTHS requirement for a 10w30 over a 5w30 they both require a minimum 2.9 most the time the HTHS is the same between these grades. a 2.9-3.1 much higher and they cannot pass the fuel economy requirements. The minimum for a 5w20 is 2.6. Again this number varies by the particular blends ability to meet the fuel economy requirement. SOme are up to 2.9 some ar edown near 2.6 the rough mean difference is .3 between any. Are you going to say you trust production tolerance to garantee .3 differnce if your engine really needs .3 hths difference for its durability?


Normally, no. But this is in extreme heat and freeway driving is known to produce fairly high oil temps. I wouldn't be surprised if the oil was running 220 degrees or more.

Please refresh my memory. I can't scroll back up without erasing what I've already written. Can you elaborate on these fuel economy requirements and were these in effect when the car was produced? I'm really asking, I'm not trying to be smart.

As for the HTHS, going from your numbers alone, there could be a HTHS difference of .5. I consider that signifigant. It *could* be as low as 2.6 which we all know is the lowest acceptable HTHS to prevent excessive wear. Personally, I don't want an oil that's only capable of preventing "excessive" wear. I want something with a huge safety margin. With that said, I would feel even less comfortable if the car spec'd a 30wt which would mean the minimum the manufacturer designed it to never see less than a 2.9.

 

[Bryanccfshr]

OK good examples of your boost cycles. It is nice that you have an OIL temp gauge. I have been trying to tap my jeep for one and there is no way to do it. I can use a temp gun to read the pan temp but that is never the same as the load temp and we know that as soon as we unload the engine it loses temperature quickly.

 

[aquariuscsm]

Originally Posted By: BuickGN
Originally Posted By: Bryanccfshr
Originally Posted By: BuickGN
Originally Posted By: Bryanccfshr
Do you understand the practical differences between these very similar multiviscosity oils? Does the ILSAC rating that they all meet require more stringent wear protection for one grade over the other?...tell me what grades have more stringent requirements outside of viscosity which again is only a nominal difference.


Then why don't they spec a 20wt from the factory for slightly better fuel economy and all that other stuff the thin guys love to talk about?

What about the HTHS difference. I would venture a guess that since they spec'd a 10w-30 and not a 5w-30, there may be a higher HTHS requirement for that engine.



There is no more stringent HTHS requirement for a 10w30 over a 5w30 they both require a minimum 2.9 most the time the HTHS is the same between these grades. a 2.9-3.1 much higher and they cannot pass the fuel economy requirements. The minimum for a 5w20 is 2.6. Again this number varies by the particular blends ability to meet the fuel economy requirement. SOme are up to 2.9 some ar edown near 2.6 the rough mean difference is .3 between any. Are you going to say you trust production tolerance to garantee .3 differnce if your engine really needs .3 hths difference for its durability?


Normally, no. But this is in extreme heat and freeway driving is known to produce fairly high oil temps. I wouldn't be surprised if the oil was running 220 degrees or more.

Please refresh my memory. I can't scroll back up without erasing what I've already written. Can you elaborate on these fuel economy requirements and were these in effect when the car was produced? I'm really asking, I'm not trying to be smart.

As for the HTHS, going from your numbers alone, there could be a HTHS difference of .5. I consider that signifigant. It *could* be as low as 2.6 which we all know is the lowest acceptable HTHS to prevent excessive wear. Personally, I don't want an oil that's only capable of preventing "excessive" wear. I want something with a huge safety margin. With that said, I would feel even less comfortable if the car spec'd a 30wt which would mean the minimum the manufacturer designed it to never see less than a 2.9.


^^20W50 and 20W50 only my brutha!

.........see my sig

 

[aquariuscsm]

But in all seriousness,I wouldn`t even think of running anything thinner than a 10W30/40 in a place as hot as AZ.

 

[Bryanccfshr]

Originally Posted By: BuickGN
Originally Posted By: Bryanccfshr
Originally Posted By: BuickGN
Originally Posted By: Bryanccfshr
Do you understand the practical differences between these very similar multiviscosity oils? Does the ILSAC rating that they all meet require more stringent wear protection for one grade over the other?...tell me what grades have more stringent requirements outside of viscosity which again is only a nominal difference.


Then why don't they spec a 20wt from the factory for slightly better fuel economy and all that other stuff the thin guys love to talk about?

What about the HTHS difference. I would venture a guess that since they spec'd a 10w-30 and not a 5w-30, there may be a higher HTHS requirement for that engine.



There is no more stringent HTHS requirement for a 10w30 over a 5w30 they both require a minimum 2.9 most the time the HTHS is the same between these grades. a 2.9-3.1 much higher and they cannot pass the fuel economy requirements. The minimum for a 5w20 is 2.6. Again this number varies by the particular blends ability to meet the fuel economy requirement. SOme are up to 2.9 some ar edown near 2.6 the rough mean difference is .3 between any. Are you going to say you trust production tolerance to garantee .3 differnce if your engine really needs .3 hths difference for its durability?


Normally, no. But this is in extreme heat and freeway driving is known to produce fairly high oil temps. I wouldn't be surprised if the oil was running 220 degrees or more.

Please refresh my memory. I can't scroll back up without erasing what I've already written. Can you elaborate on these fuel economy requirements and were these in effect when the car was produced? I'm really asking, I'm not trying to be smart.

As for the HTHS, going from your numbers alone, there could be a HTHS difference of .5. I consider that signifigant. It *could* be as low as 2.6 which we all know is the lowest acceptable HTHS to prevent excessive wear. Personally, I don't want an oil that's only capable of preventing "excessive" wear. I want something with a huge safety margin. With that said, I would feel even less comfortable if the car spec'd a 30wt which would mean the minimum the manufacturer designed it to never see less than a 2.9.

On the HTHS topic yes that is the max possible difference or as you see it the worst case scenario. I express mine in mean numbers to avoid having to average all the PDS's I could pull.(to much work for our pace of discussion)

OK Fuel economy pass fail criteria from SWRI
Pass/fail criteria for ILSAC GF-4 and API SM (minimum %FEI versus ASTM BC)

SAE 0W-20 and 5W-20 viscosity grades:

2.3% min. after 16 hours aging (Phase I FEI)

2.0% min. after 96 hours aging (Phase II FEI)

SAE 0W-30 and 5W-30 viscosity grades:

1.8% min. after 16 hours aging (Phase I FEI)

1.5% min. after 96 hours aging (Phase II FEI)

All other SAE viscosity grades:

1.1% min. after 16 hours aging (Phase I FEI)

0.8% min. after 96 hours aging (Phase II FEI)
More info here
http://www.swri.org/4ORG/d08/GasTests/VIBtest/default.htm

Reviwing that data I must concede that a 10w30 May get away with a very slightl/higher HTHS than a 5 or 0w30 due to it having a less stringent FE pass/fail factor.

 

[BuickGN]

Originally Posted By: Bryanccfshr
OK good examples of your boost cycles. It is nice that you have an OIL temp gauge. I have been trying to tap my jeep for one and there is no way to do it. I can use a temp gun to read the pan temp but that is never the same as the load temp and we know that as soon as we unload the engine it loses temperature quickly.


All it does is worry me. Now that I know the trends, I think I would be happier with a warning light set to come on at 300F. Otherwise I worry myself with a quick 30 degree increase for no reason.