15W-40 oil in Oregon weather? (1 Viewer)

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Joined
Nov 16, 2013
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Location
Saint Helens, OR.
Is 15W-40 ok to use on my 97 FZJ80 year around in Oregon weather, without damaging the engine? Very occasionally goes down to teens on winter time but it's usually maybe upper 20s - 40s... lately its been warm (for us) here. My 80 is not leaking oil but its consuming oil. Maybe a quart or less every 1000 miles. Been using 5W-40 syn oil. Mobil 1 TDT in the past currently I am using Rotella T6. I just want to try the 15W-40 on my next oil change but weather here is changing slowly to cold.
 
Yes Always let any engine idle a short time anyway. Operate at light load until warmed up. Colder=longer.
 
The owners manual gives temp ranges for recommended oils. 10-30 goes down to 0F, so 15 weight should be just fine given your post.
 
I ran Delo 15w-40 in Northern Idaho for several years with no issues. If you have any steep grades to climb you will notice a bit of a power loss, but beyond that, it is actually better for the engine--recommended weights are a compromise between emissions/efficiency and engine protection.
 
The W stands for "Winter" not weight.... it's the viscosity of the oil in sub freezing temperatures, then the viscosity once warmed up.

Motor Oil Viscosity Grades Explained in Layman's Terms

So once warmed up, a 5w40, 15w40, 10w40.... all react the same way from a viscous level....

In my vehicles (not just 80 series), if I am smoking on startup (usually leaky valves) or seem to be losing oil without smoking on startup (burning past the rings, but not so bad you see it behind you) then I will bump up to the next thickness..... In my AE95 I run 20w50 and in the FZJ80 I've been running 10w40, but may bump it up to 20w50. My FJ40 will start with 10w40 (given it has an old 350 in it), and my IS300 I ran 5w30 or 10w30, whichever I grabbed from the shelf.
 
Looking at the "for everyone else but USA" oil selection chart for the 1FZ, 15w is good for 14F starts.

AU viscosity chart
1FZFE motor
20w50 oil- -7C deg to 38C plus ; 19F to 100F plus
15w40 oil -10C deg to 38C plus; 14F to 100F plus
10w30 oil -18C to 38C deg; 0F to 100F
5w30 oil -30C to 38C deg; -22F to 100F
 
I too live in Western Oregon and have run 15W-40 in my 40, 60, and now 80 for most of the 20 years I've lived here. Perhaps if I lived east of the Cascades I'd use something else. And that is only a perhaps.
 
Thanks for the replies. I will try a dino 15W-40 oil. I have a trip to Bend oregon soon, we'll see how it do going through the mountains
 

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