Which oil for hot summers in Houston, TX?
- Thread starter djmc
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Used oil analysis
My old man got 180K out of an '81 Pontiac Bonneville V8 using whatever Jiffy Lube or Wal Mart had in the bulk tanks. Knowing him, it was probably straight 30, or 10w-30 the entire time.
Your cooling system will negate pretty much any differences in ambient temperature, or in other words, since your cooling system keeps your engine at about 200 degrees, it won't really matter if it's 70 or 100 outside. Any localized hot spots in your engine will probably occur regardless of what the ambient temperature outside the engine is.
I'd just use whatever the owner's manual calls for, so long as it's SM/GF-4 rated.
Your cooling system will negate pretty much any differences in ambient temperature, or in other words, since your cooling system keeps your engine at about 200 degrees, it won't really matter if it's 70 or 100 outside. Any localized hot spots in your engine will probably occur regardless of what the ambient temperature outside the engine is.
I'd just use whatever the owner's manual calls for, so long as it's SM/GF-4 rated.
Amsoil ATM 10w-30 for 1992 Volvo 240 DL Wagon B23F Non Turbo
160M miles in Houston.
160M miles in Houston.
Use a 5w30 full synthetic in the Ford.....
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so 140°f is too hot for conventional oil?
Not 140f. 220f. I thought that driving style puts him into the severe service catagory. I hope you're right oil temp goes down in stop and go even after air flow is removed and radiant heat from pavement is added. I might be more comfortable with extending intervals, myself.
Radiant heat is always there regardless of speed. It is the lack of airflow that that challenges a cooling system. Everyone with an oil temperature gauge has reported drops in oil temperature when coming off of highway travel into stop and go. The engine itself is simply not putting out enough energy to keep the oil temperature up to the operating temperature. Oil will also dissipate it's heat much quicker than water will so it will coll quicker than water. So even if the area around the oil pan id 140° F the oil is going to dissipate it's heat away from the oil pan towards the pavement. (heat always dissipates to cool and in this case the pavement is cool, so when you slow down in traffic your engine is actually giving heat tot he pavement because your 180-220 degree oil is hotter than the surrounding area)
Of course there are a lot of cars and trucks on the road with coolant oil heat exchangers. This will actually keep the oil hotter longer in this situation than if you didn't have one. This is actually a good thing since it keeps all the fluids in the system at close to the same temperature.
Watch the water temperature gauge in traffic . The oil temperature when pulling a heavy load, going through extreme grades or driving at extra legal speeds for extended periods of time.
Of course there are a lot of cars and trucks on the road with coolant oil heat exchangers. This will actually keep the oil hotter longer in this situation than if you didn't have one. This is actually a good thing since it keeps all the fluids in the system at close to the same temperature.
Watch the water temperature gauge in traffic . The oil temperature when pulling a heavy load, going through extreme grades or driving at extra legal speeds for extended periods of time.
Patman
Staff member
Most of the time this is true, but not in the very hot summer. In the very hot summer if I've got the AC blasting and I'm on the highway my oil will be at about 210F, but once I get off the highway and I'm stuck in traffic, if my AC is still on I've seen my oil temps go close to 230F. I've never seen the oil temps get anywhere near that hot at a steady highway speed though, only in stop and go.
Same here. I have observed the same increase in oil temp in traffic with a car and a motorcycle.
That isn't true for all vehicles. I suspect it has to do at least partially with air circulation around the oil pan. Back in the olden daze, 30+ years ago, with full time fans stirring up the air and much less densely packed engine compartments, my car's oil temp used to drop in traffic compared to a freeway run.
Interesting and it sounds like heat soak due to lack of airflow immediately following a steady state. How long does the event last? In theory the heat shoud dissipate through radiation given enough time, but I believe your spike is another good indication why GM requires a synthetic oil for the Corvette.
None of my oil pans are usually closer to the pavement than 14" and I have a crankshaft driven cooliing fan. So perhaps my mind is set towards my specific situation.
Another question is an oil temperature of 230°f all that harmfull?
None of my oil pans are usually closer to the pavement than 14" and I have a crankshaft driven cooliing fan. So perhaps my mind is set towards my specific situation.
Another question is an oil temperature of 230°f all that harmfull?
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Patman
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The oil temps will continue to climb the longer I am stuck in traffic, they won't come down until I am moving at a faster rate of speed.
I do believe this is one of the reasons why the Corvettes require synthetic. I don't think 230F temps are harmful at all, as long as you don't see those temps every single day. A lot of Corvette guys who road race have seen temps as high as 300F without any immediate problems. Although in the long term I'm sure temps that high aren't helping, especially if they are running an oil that has a lower HTHS number (such as 3.0 or so)
I also imagine the engineers and designers didn't have sitting in heavy traffic in mind when they designed the vette. My perspective is scewed towards trucks and 4x4's with cooling systems designed for low speed high load.. So from one extreme to another.. What about the middle? How does your wifes Honda ofr a minivan react?
Patman
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I wouldn't know, since her Honda does not have an oil temperature gauge. I don't think there are any minivans out there that have them either.
The Mann oil filter is available for $7.12 each or $51.21 for a case of 10 when purchased online. If you want the name of the vendor, PM me.
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