Since you are in Idaho, I imagine you'll see plenty of cold weather driving, as well as mountain driving and hot summers.
If the engine runs well on 5W-20, then it might still be worth a try. The 5W-20 oils that meet Ford and Honda's specs are usually pretty good oils, and are often synthetic blends.
If 5W-20 works it may be better suited for the cold weather and provide slightly better mpg.
If you want to look for 'thin' 5w30 and 10w30 oils there is a sticky in this forum that might help you find the right oil.
I don't see what would be wrong with a 0W-20 in the winter and a 10w30 for the summer heat.
If it was a good 0W-20 like the new Amsoil, or Mobil 1 0W-20, or a stout 5W-20 like the Redline 5W-20.... I also don't see what would be wrong with running these oils all year long.
I prefer 0W-x oils that are full synthetic and tend to be on the thick side at high temperatures.
When there is a wide range of temps, and mountain driving like we see in the Rockies in Colorado...I'm convinced that full synthetic can be better.
I run Mobil 1 0W-20, 5W-20, and Pennzoil Platinum 5W-20 in our Honda Element.
GC 0W-30, Elf Excellium 0W-30, and maybe I'll try Pennzoil Platinum 5w30 in our Subaru Outbacks.
Delvac 1 5W-40 in our Duramax Crew Cab.
Redline 5W-40 or GC 0w30 in our older BMW's, and Mobil 1 0W-40 in the newer BMW's and Mercedes.
Pennzoil Platinum 5w30 in our Chevy Corsica.
When I just had to make a drive from Vail to Salt Lake and back and it was over 100 degrees during much of the trip.....I was really happy to have a 'thick' full synthetic 0w30 in the engine.
I really like this comment in a Volvo oil bulletin:
"Synthetic oils meeting SAE 0W-30, 5w30, or 0W-40 and complying with oil quality requirements are
recommended for driving in areas of sustained temperature extremes (hot or cold), when towing a trailer over
long distances, and for prolonged driving in mountainous area."
http://theoildrop.server101.com/forums/s...true#Post928396
I'm convinced that 'thicker' oils, full synthetic oil, better base stocks, and higher additive levels..... make a positive difference when there is any sort of demanding driving.
I'm also convinced that Lube Control LC-20 in the oil and FP Plus in the fuel is worth using.
And, Auto RX is a great way to gently clean a used engine.
I no longer judge an engine until after I've run these products and I feel the engine internals are clean.
