10W-40 at 40 F

Messages
372
Location
Rancho Cucamonga, CA
I've been running Pennzoil 10W-40 in my '95 Hyundai Accent (to help w/oil consumption this summer) and would like to continue to do so through the winter. The "winter" here never reaches colder than about 40 F -- and that's first thing in the morning. Once daylight hits, it's never colder than 50. Does anyone anticipate any problems with this oil in this weather? The car is driven in a pre-dawn/early afternoon work commute of 30 miles each way. I recently completed a double treatment of Auto-RX with this oil in this car. The reason I wanted to stick with 10W-40 is purely to get a UOA with this brand/grade...since there are none posted on this site. If the UOA wasn't a factor, I'd probably switch back to 10W-30 or 5W-30 in the winter. Hyundai recommends anywhere from 5W-30 to 20W-50 in the manual, with a "preferred" grade of 10W-30. Any harm to sticking with 10W-40 through a mild winter?
 
Messages
453
Location
Galveston, TX
quote:
Originally posted by timzak: I've been running Pennzoil 10W-40 in my '95 Hyundai Accent (to help w/oil consumption this summer) and would like to continue to do so through the winter. The "winter" here never reaches colder than about 40 F -- and that's first thing in the morning. Once daylight hits, it's never colder than 50..... .....Any harm to sticking with 10W-40 through a mild winter?
Back home in New York, I used 20w-50 and straight grade HD-30 in 28 degree F weather as a matter of course. The cars I had then are still running good now, on the original engines.
 
Messages
810
Location
Greece
I have used 10W40 for 3 years(Opel synthetic 5W40 now) ,Mobil and Valvoline durablend.I was very satisfied with Mobil in the winters ,9-10 F ,easy start up no valve noises.The third winter i was using durablend i and had experienced some awful metalic noises when temperatures were around 17 F and below , for the first 20 sec on start up early in the morning.No problems when temp was above 17F or after the first 20 sec. The durablend was doing better in the summer handling hot weather better and keeping engine temperature lower though. So..i believe a good 10W40 will be fine in 20 F and above.
 

timzak

Thread starter
Messages
372
Location
Rancho Cucamonga, CA
Thanks guys. I wasn't concerned about anything breaking [Big Grin] but wasn't sure if I'd be doing the engine any favors, either, with the thicker oil in cooler weather. Sounds like it's a go, then. I'll continue on with Penn 10W-40. Expect a UOA before Christmas.
 
Messages
47,644
Location
Duvall WA - Pacific NW USA
Well you may have a freeze every 20 years or so in Rancho C-munga (I was born in Fullerton) - but most any 10W will NOT have a problem there. Have you considered Amsoil 10W-40? I hadn't personally used that oil - now that I'm "on" it (in the 855) it's a great oil.
 
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