Oil Viscosity help which one to use?

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I have an old Volvo with 200k miles(2.4l NA) and I use full synthetic oil (M1HM) and change it once per year (about 5000 miles-don't drive much) Hasn't burned anything in the last 5k and blowby is minimal. I live in Minnesota where the coldest I have had to drive this car in was about -10 F and the average summer day is 70 F to 85 F but there are times when it can get over 90 F. The first time I changed the oil I put in 10W-30 but upon looking at the viscosity chart in the owners manual it says that 10W-30 is only good until -4 F and 5W-30 is only good until 86 F. My question is can full synthetic 5W-30 and 10W-30 last beyond/below the temperatures in this chart or do I need to switch between seasons or use 5W-40. This doesn't seam right I thought full synthetics could withstand extreme temperatures?
 
Why not use a euro spec 0w40 year long? The oil is good at minimum for 10k miles if not more, so it should suite you great. M1 0w40 is at walmart right now for 22.88 for 5 quarts
 
Yes, I believe full synthetics can last beyond/ below the temperatures in that chart, IMO.
That chart was written when oils were probably SH (predominately Gr. 1 and lesser quality than modern oils).

If it's not using oil, I'd run 5w30 in winter and 10w30 in summer...If you are using oil, bump it up to 0w40 (Mobil 1 or Castrol Edge)....
 
That chart represents Volvo's requirements most likely for conventional oil. You need to consider Mobil 1's limits. M1 5w-30 would easily handle both ends of your temperature requirements and keep to your once a year change schedule.
 
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I think pbm summed it up. Todays synthetics are far better than those dino oils of 97. A 5-30 synthetic IMO will do you fine in the fickle MN weather. Hit 98 here this afternoon. We finally got a nice shot of rain too.
My Scion recommends 5-20 and the Xterra gets 5-30
 
Concur with the above. No reason you couldn't run a 5w30 year round for your yearly OCI.

If you want to abide strictly by the owners manual there's no reason you couldn't also run a 0w40 or 5w40 year round for your annual OCI as well.

Either course of action will be just fine!
 
If I did not start it much below 0F, the M1 10w-30HM is a great oil and worth sticking with it. I use it in most vehicles I take care of (ours, and my parents'). I live in a milder climate where cold cranking visc. is completely unimportant, and not in the Gopher state.

If you have to use it much in the very cold, then the 5w-30 HM variant is a better bet, though not as robust an oil overall. A synthetic 10w is good in fairly cold temps, too - just not as far.
 
That chart looks a bit bogus; even in 1997 a 5W-30 and 10W-30 should have the same upper ambient temperature limits as they are both a 30 after the dash. It's just the lower temperature limits that should be different.
 
Originally Posted By: TheBeaz
I live in Minnesota where the coldest I have had to drive this car in was about -10 F and the average summer day is 70 F to 85 F but there are times when it can get over 90 F.


nice summer / brutal winter
shocked2.gif
 
It's not like we are talking air cooled engines like a old VW Beetle where the outside temps would be a factor . *Isn't this why guys in Texas can run a synthetic 5W20 all year long (including summer) because of radiators ?
 
Originally Posted By: TheKracken
Why not use a euro spec 0w40 year long?

This would be my first choice, or whatever dual rated HDEO you happen to find left. Given the price of M1 0w-40 quoted in the States, it's hard to go wrong with that.
 
Originally Posted By: TheBeaz
I have an old Volvo with 200k miles(2.4l NA) and I use full synthetic oil (M1HM) and change it once per year (about 5000 miles-don't drive much) Hasn't burned anything in the last 5k and blowby is minimal. I live in Minnesota where the coldest I have had to drive this car in was about -10 F and the average summer day is 70 F to 85 F but there are times when it can get over 90 F. The first time I changed the oil I put in 10W-30 but upon looking at the viscosity chart in the owners manual it says that 10W-30 is only good until -4 F and 5W-30 is only good until 86 F. My question is can full synthetic 5W-30 and 10W-30 last beyond/below the temperatures in this chart or do I need to switch between seasons or use 5W-40. This doesn't seam right I thought full synthetics could withstand extreme temperatures?



10w-30 is good to -15 F I believe. It depends on the specific blend in question. 5w-30 takes the heat just fine. Oil has improved tremendously since your OM was printed.

I prefer 10w-30 for my application. You said you already put 10w-30 in it once. Did you have any problems with cold starts?
 
10w-30 must be no thicker than 7100 CCS cP at -25F.

5w30, no thicker than 6600 CCS cP at -30F

Despite the chart you listed, 5w30 is not some magic sauce that allows you to start the car at -100, nor will 10w30 cause the engine to grenade at -5F.

https://www.mobil.com/English-US/Passenger-Vehicle-Lube/pds/NAXXMobil-1-High-Mileage-Oils

M1 HM 5w30 and M1 10w30 have the same pour point listed, -39F.

I would keep using the M1HM 10w30 if it's working well for you. You should be able to start the car at -25F. Beyond that is questionable.
 
When it was like -5 or -10 it started up like a champ and the engine sounded fine.
 
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