Back in the past say 20 years ago my father always told me to go from 5w30 to 10w30 in the summer months. Is this still an accepted practice or is there no need to do so? Would a 10w30 be more shear stable under high heat say towing a camper?
Summer oil switch
- Thread starter Camprunner
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With modern oils, its not necessary to switch from a 5w to a 10w. Years ago a 10w may have been more sheer stable. Now having said that, I'm running 5w20 in my Hyundai in the winter and 5w30 in the summer, my owners manual supports doing this. In my truck for towing, I'm running Quaker State Ultimate Durability 5w30.
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We live a few mils from the Florida line and experience long hot summers.
My wife and I use 5W20 oil year around in both our vehicles and did the same in others we have owned.
Oil fill cap indicates 5W20 and owners manual recommends it too.
Nothing has blown up yet.
My wife and I use 5W20 oil year around in both our vehicles and did the same in others we have owned.
Oil fill cap indicates 5W20 and owners manual recommends it too.
Nothing has blown up yet.
Originally Posted By: Dallas69
No need to imo
After your engine gets up to operating temp they are both 30wt
There are differing shear stabilities depending on the service category within any multi-grade. AN ACEA A3/B3/4 5w30 will have a significantly higher HTHS than an ILSAC GF-5 PCMO.
The WT term is not correct.
No need to imo
After your engine gets up to operating temp they are both 30wt
There are differing shear stabilities depending on the service category within any multi-grade. AN ACEA A3/B3/4 5w30 will have a significantly higher HTHS than an ILSAC GF-5 PCMO.
The WT term is not correct.
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Vehicles today are able to maintain pretty consistent oil temps, so there is no real need to deviate from the recommended viscosity. I typically only buy 10W30 or 10W40 if I get a REAL good deal, otherwise it's 5W30 and 5W20, including my off road toys and drag car.
At operating temperature, the 5w30 and 10w30 (of the same brand) are probably going to be almost identical so it's not really going to make any difference. Only difference would be that when it's very cold outside (which is not going to be the case during the summer), the 5w30 would be much thinner and easier to start. On the other hand, there would be a difference between 5w30 in the summer and 5W-20 in the winter. My wife's Kia says both viscosities are okay and I'm thinking about running 5-20 in the winter and 5-30 during the summer. Even though they are both 5W oils, the 5-20 is going to be significantly thinner and easier to crank when very cold as compared to the 5-30. So, I see no point at all in changing to 10-30 from 5-30 during the summer.
gathermewool
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Originally Posted By: ARCOgraphite
Originally Posted By: Dallas69
No need to imo
After your engine gets up to operating temp they are both 30wt
There are differing shear stabilities depending on the service category within any multi-grade. AN ACEA A3/B3/4 5w30 will have a significantly higher HTHS than an ILSAC GF-5 PCMO.
The WT term is not correct.
Colloquially, xxWT is just fine, IMO. We all know that he means the 100C viscosity (KV) range, right?
OP, if you're worried about high-temp shearing, then follow ARCOgraphite's advice and choose a shouted oil (higher HTHS) instead of a lower-index multi-grade.
Originally Posted By: Dallas69
No need to imo
After your engine gets up to operating temp they are both 30wt
There are differing shear stabilities depending on the service category within any multi-grade. AN ACEA A3/B3/4 5w30 will have a significantly higher HTHS than an ILSAC GF-5 PCMO.
The WT term is not correct.
Colloquially, xxWT is just fine, IMO. We all know that he means the 100C viscosity (KV) range, right?
OP, if you're worried about high-temp shearing, then follow ARCOgraphite's advice and choose a shouted oil (higher HTHS) instead of a lower-index multi-grade.
Originally Posted By: Camprunner
Back in the past say 20 years ago my father always told me to go from 5w30 to 10w30 in the summer months.
I didn't even bother with that 20 years ago.
Back in the past say 20 years ago my father always told me to go from 5w30 to 10w30 in the summer months.
I didn't even bother with that 20 years ago.
Run the 10w30 above 0 degrees Fahrenheit. 5w30 below. Plain and simple.
You could use a 10w30 in the warmer months if you wanted to.
The only real advantage is that the grade can often be found on closeout dirt cheap, which is the reason that I have a fair amount of 10w30 in my stash.
Current 5w30 grade oils don't seem to suffer much shearing in a typical OCI.
This was not always the case, although a current 10w30 might shear almost as much.
The only real advantage is that the grade can often be found on closeout dirt cheap, which is the reason that I have a fair amount of 10w30 in my stash.
Current 5w30 grade oils don't seem to suffer much shearing in a typical OCI.
This was not always the case, although a current 10w30 might shear almost as much.
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That's what my OM stated. Used 0W-40 instead. No regrets to date.
Originally Posted By: Merkava_4
Run the 10w30 above 0 degrees Fahrenheit. 5w30 below. Plain and simple.
Originally Posted By: Merkava_4
Run the 10w30 above 0 degrees Fahrenheit. 5w30 below. Plain and simple.
gathermewool
Site Donor 2025
Originally Posted By: gathermewool
Originally Posted By: ARCOgraphite
Originally Posted By: Dallas69
No need to imo
After your engine gets up to operating temp they are both 30wt
There are differing shear stabilities depending on the service category within any multi-grade. AN ACEA A3/B3/4 5w30 will have a significantly higher HTHS than an ILSAC GF-5 PCMO.
The WT term is not correct.
Colloquially, xxWT is just fine, IMO. We all know that he means the 100C viscosity (KV) range, right?
OP, if you're worried about high-temp shearing, then follow ARCOgraphite's advice and choose a shouted oil (higher HTHS) instead of a lower-index multi-grade.
"stouter" Auto-correct to "shouted," for clarification
Originally Posted By: ARCOgraphite
Originally Posted By: Dallas69
No need to imo
After your engine gets up to operating temp they are both 30wt
There are differing shear stabilities depending on the service category within any multi-grade. AN ACEA A3/B3/4 5w30 will have a significantly higher HTHS than an ILSAC GF-5 PCMO.
The WT term is not correct.
Colloquially, xxWT is just fine, IMO. We all know that he means the 100C viscosity (KV) range, right?
OP, if you're worried about high-temp shearing, then follow ARCOgraphite's advice and choose a shouted oil (higher HTHS) instead of a lower-index multi-grade.
"stouter" Auto-correct to "shouted," for clarification
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