Thickest oil grade you have run in winter, summer?

[AutoMechanic]

Thickest in the winter 10W-40 in my Mazda truck and Ford Van. Thickest in the summer 10W-40 in the van and truck. Plan on maybe putting a quart of 20W-50 in the truck this summer to see how it does. Everything I own gets factory spec oil year round, just makes me feel better about everything.

 

[Slow Car Sport Mode]

20W-50 as partial fill.

 

[Tom36852]

For what it is worth, I have been running SuperTech 5w-30 Full Synthetic or High Milage Full Synthetic with a Motorcraft filter on my 2011 F-150 3.5 EcoBoost year round here in Anchorage Alaska. During the dead of winter our daily avg high is around 10 degrees F with a low around 0 degrees F. We can have cold snaps down to -35 degress F that last a few weeks or three. My F150 lives outside and doesn't have a block heater. Besides some slower cranking, which is more likely to be attributed to low battery voltage from cold temps, I have never had any issues. During the summer we move up to highs in the 70s/80s with lows at the 50/60s. I run the truck in excess of the Ford Algorithm. Typically I change it around "130 %" mark by resetting it back to 100% when the "oil life indicator" drops to 70%. I have to add 1 qt between changes. Each change is about 7500 miles. The truck currently is sitting just over 180K miles. The only major mechanical repair has been the transmission. Around 160k it was replaced.

 

[350Rocket]

15w50 in my 1976 Oldsmobile 350 years ago in summer. But it seemed like the valve train was noisier with it despite the improved oil pressure. This is a high mileage engine but still runs strong. I usually run 0w40 m1.
Wintertime I haven't run anything thicker than that. Often I have ran 0w30 in winter.

 

[Astro_Guy]

Back in the college days in upstate NY, late 70's through 1980, I ran Quaker State SAE 30 in an air cooled Chevy Corvair. Minus 10 F wasn't uncommon in January. It was tough starting at minus twenty...

 

[Heywood_6078]

Was wondering what’s the thickest oil grade you ran in winter? Or summer months. Me, I’ve ran 10w30 HM that was SL rated in winter. In summer it would have been Valvoline Synpower with sodium add pack and 10w30 grade

Straight 30 weight Havoline conventional oil. Year around.
Cold winters and hot summers.
Bought a new ford f-150 in 1993 and ran this oil in it until I sold the
truck 12 yrs later with 294,000 miles on it.
Had the inline 300 straight six. Awesome engine.

 

[4WD]

15W40 in 2010 5.3L GMC … but it’s common for me to roll over to 5W30 in my 0W20 spec’d engines … I‘m in the south and not concerned with tiny MPG gains … 0W40 has my now …

 

[DGXR]

For a couple years I ran 20w-50 in a 1986 Mazda B2000 pickup. Our lowest winter temps are around 25F so it wasn't a problem. I ran the high viscosity stuff to help reduce oil consumption -- that engine was seriously clapped out, but it did the job until I could get something nicer.

 

[Malo83]

Ran 20w50 in my Silverado back in the day, year round.

 

[ripcord]

Ran 20w50 in my Silverado back in the day, year round.

Same. Except in a loose and tired Dodge slant six. Doesn't get that cold here though.

 

[Tifosi]

Thickest oil ever ran for all around was 10W-40, that was before 0W-XX appeared on the market.

 

[MSCH]

SAE 60 in an old Harley Panhead.

 

[SubieRubyRoo]

Ran the Motul 4100 Power 15w50 in my 2007 Impreza awhile back, went in in Fall and came out in late Spring.

 

[Luftmasse]

20W-50 in an older civic.

 

[Mainia]

5W-40 Minnesota.

 

[Rogueman2016s]

Was wondering what’s the thickest oil grade you ran in winter? Or summer months. Me, I’ve ran 10w30 HM that was SL rated in winter. In summer it would have been Valvoline Synpower with sodium add pack and 10w30 grade

2008 Hyundai sonata 5w20, 2010 Subaru Impreza 5w30 anything else I owned took 0w20 year round no need to switch.

 

[Crash Bandicoot]

Once put in Mobil 1 15w50. It was on clearance at Walmart for practically nothing. I quickly pulled up an UAE owner’s manual for a car with the same engine and it said I could run that oil so run it I did. Normally run 0w40 Euro year round in Scottsdale 120° high never really gets below freezing.

 

[zray1]

Once put in Mobil 1 15w50. It was on clearance at Walmart for practically nothing. I quickly pulled up an UAE owner’s manual for a car with the same engine and it said I could run that oil so run it I did. Normally run 0w40 Euro year round in Scottsdale 120° high never really gets below freezing.

I used the M-1 15w-50 year round when I lived in central Texas for all of my classic cars. Moving to NE Oklahoma about 10 years ago I went to M-1 0w-40 FS for the winter, then all year round. I never had any difference in oil pressure between the two oils (cold or hot) , which was a surprise.

Z

 

[Chris142]

Dad said in his 67’ CUDA with 273 he ran Pennzoil SAE 40 for longest time. It touted “with Z-7” on cardboard can

My dad used that but 10w-40 in his beetles.

 

[Sedin26]

I used 20w50 and straight 30 weight in my 93 Tercel in winter but it rarely gets below freezing here.

On the farm, where it would get down to -40c, lots of the old equipment would use 15w40 or 10w30. Had to be plugged in to start at those temps.