Im ignoring the OLM during towing......

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Im gonna ignore my OLM during heavy towing with my 2008 silverado vortecmax. During long hill climbs I see my oil pressure dropping due to heating up of the oil, I am not seeing that 10 psi per thousand rpm rule during this kind of towing. I also pulled the dipstick when refueling and burned my hand horribly on the stick and saw some smoke coming from the dipstick tube!! I still cant believe the gm calls for a 5w30 under all conditions in these trucks. I am running Pennzoil Platinum 5w30 by the way. I got 3200 miles on this oil at 60 percent on the OLM. I also run an aftermarket computer tuner on this truck. I will run a UOA at around 4 or 5 thousand miles and see from there how much longer I can punish this oil. Im thinking at least a 10w30 with a bit higher HTHS and volitility will help in the summer months. Synthetic 10w30 flows better then conventional 5w30 at startup if I am not mistaken? What does everyone think??
 
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Under those conditions I think Redline oil would be a great go to. PP is a good oil also, I would bump the Viscosity, maybe look at Rotella T 5w-40 syn as well.
 
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As long as GM spec'd that oil I think you'll be fine. Before I changed anything see what the UOA tells you. GM spec'd that oil for a reason, and I'm pretty sure they have taken towing into account. Now if they've given you other options then that would be a different story. JMO AD
 
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Another vote for Redline. Maybe a 40wt with the amount of heat yours seems to be seeing.
 

FZ1

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Gimmee a break re Summer in Mich. The 5-30 is fine. Synthetic runs cooler. Thinner runs cooler.
 
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Synthetic 10w30 in the summer, synthetic 5w30 in the winter. If you're doing alot of towing I'd first consult the UOA and compare it to what the OLM is telling you. This should give you an idea of accurate that thing is with the towing you're doing. Change the oil accordingly.
 

JHZR2

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more or less any oil will smoke if you pull the cap after running it to temperature. Without very detailed analytical equipment, you don't know if it is oil, fuel vapors, moisture, etc. It surely doesnt hurt to bump up a grade viscosity-wise under those conditions, or go to something really robust, like redline. I'd like to know what UOAs for a duration of this sort of use look like before making any real calls though...
 
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Redline is NOT API-certified. If you are using your vehicle hard, it is more likely you may need warranty work on it - don't use a non-API certified oil during this period! What you are using is a great oil - it will survive the service just fine!!!
 
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 Originally Posted By: addyguy
Redline is NOT API-certified. If you are using your vehicle hard, it is more likely you may need warranty work on it - don't use a non-API certified oil during this period! What you are using is a great oil - it will survive the service just fine!!!
You can't really say if it will survive just fine without seeing what kind of abuse it's up against or a UOA to see how much life is left in it. Redline would greatly reduce the chance of it needing warranty work. Besides, whatever damage might be done would rear it's head after the warranty period most likely. The fact that the oil pressure is falling off is pretty convincing that something needs to be done quickly.
 
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Oil pressure may fall a bit, but it's not going to grenade the motor. GM tested this engine, in towing conditions, I'm sure, with basic 5W-30 dino in it. Synthetics have tougher oil films than conventionals, so the PP will do fine.
 
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But what if 5W-30 is the CAFE compromise and not actually the "best" viscosity for this engine under extreme conditions? I do find it interesting GM is one of the 30-wt holdouts. LSx do seem to prefer a thicker viscosity, like a heavy 30-wt (like an ACEA A3/B3 30-wt) or a 40-wt. I think RedLine 5W-30 or 5W-40 might not be a bad choice, I also think Mobil 1 TDT might be a good, readily available option here. One or two OCs with a more robust oil will not kill the engine, and may address his concerns. There's no reason to stick with manufacturer vis recommendations against all reason, IMO.
 
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 Originally Posted By: Ponch
During long hill climbs I see my oil pressure dropping due to heating up of the oil, I am not seeing that 10 psi per thousand rpm rule during this kind of towing. I also pulled the dipstick when refueling and burned my hand horribly on the stick and saw some smoke coming from the dipstick tube!! I'm thinking at least a 10w30 with a bit higher HTHS and volitility will help in the summer months. Synthetic 10w30 flows better then conventional 5w30 at startup if I am not mistaken? What does everyone think??
Last first.... Syn or conventional ...A 5W will flow better than a 10W... a 30 is a 30 at 100C (212F)... you would be better off with the 5W if start up wear is your concern. Yes... you can burn your pinkies on the dip stick... its right down near the manifolds where its going to pick up radiant heat as well as hot air off the radiators. The '10 psi rule' applies to any situation as I recall ... there's no difference if you are towing or not. But this 'wisdom' goes waaaaay back and might not be accurate today. What you could be seeing reduced pressure because the oil is now up to its rated weight at 100C/212F. Anyway, is your oil gauge 'calibrated' and does it have a 'linear' response?? The problem could be with the gauge and sending unit in that its not accurate and does not have a linear response. I'd drive on with the 5W-30 or whatever is the recommended grade. FWIW... you could reduce the oil temps by slowing down! and decreasing your speed up hill to decrease the engine's workload. Are you sure you aren't overloaded for the towing capacity of the truck????
 
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 Originally Posted By: addyguy
Oil pressure may fall a bit, but it's not going to grenade the motor. GM tested this engine, in towing conditions, I'm sure, with basic 5W-30 dino in it. Synthetics have tougher oil films than conventionals, so the PP will do fine.
+1 Oil pressure always dips with hot oil, as long as it is within specs it should be fine. Verify pressure with a mechanical gauge if in doubt. God only knows how many of those engines are in service under worse conditions with a 30wt oil and doing just fine. If you're worried about the OLM change the oil out when it gets to 15%-20% life remaining. AD
 
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 Originally Posted By: Ponch
.......I also run an aftermarket computer tuner on this truck........
Are you running more ignition advance than stock?
 
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 Originally Posted By: Ponch
saw some smoke coming from the dipstick tube!!
I've never saw that before and I towed a heavy boat with passenger cars and light SUV. Sounds like you have a problem with oil temperature. Do you have oil cooler? Can you measure the oil temp with IR thermometer? Maybe the aftermarket tuning puts too much stain of the engine and cooling? If so using a top notch synthetic with higher HTHS may be a band aid.
 
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 Originally Posted By: Ponch
Im gonna ignore my OLM during heavy towing with my 2008 silverado vortecmax. During long hill climbs I see my oil pressure dropping due to heating up of the oil, I am not seeing that 10 psi per thousand rpm rule during this kind of towing. I also pulled the dipstick when refueling and burned my hand horribly on the stick and saw some smoke coming from the dipstick tube!! I still cant believe the gm calls for a 5w30 under all conditions in these trucks. I am running Pennzoil Platinum 5w30 by the way. I got 3200 miles on this oil at 60 percent on the OLM. I also run an aftermarket computer tuner on this truck. I will run a UOA at around 4 or 5 thousand miles and see from there how much longer I can punish this oil. Im thinking at least a 10w30 with a bit higher HTHS and volitility will help in the summer months. Synthetic 10w30 flows better then conventional 5w30 at startup if I am not mistaken? What does everyone think??
I tow an 30ft RV behind my 2006 Sierra Denali (6.0L HO Vortec Max also) and my oil pressure is always good, coolant temp always good,but my transmission fluid runs a little higher (I have a trans temp gauge) towing. Yeah, the dipstick is hotter than [censored] when checking it hot after towing. In any event, I changed my oil 1 week before going on my trip last week towing my RV and believe me - the OLM takes into consideration towing - especially if you are using the "tow/haul" mode. I watched the OLM go from 97% when I left to 83% by the time I got home. I was driving 9hrs in texas 105+ degree heat at 70-75mph. I run 5W/30 Mobil 1 winters and 10W/30 for the summers. I want more protection with the 10W/30 when towing even though some will disagree with that statement. Summary - the OLM works and works well. I usually change my oil when the OLM gets around 20% and that works out to be between 5 and 6 thousand miles which is fine with me. Also remember, the OLM on our trucks is based on dino oil so we are doing better with the synthetics.
 
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