We've had up to -25 degrees Celsius in Toronto the last dew days and my Cherokee didnt even hesitate to start. The only issue I had was getting the doors to open as ice had sealed them shut! I snow plow commercial properties with my 2000 Jeep Cherokee and she runs strong and problem free every night! But with that being said I have made a few mods to make this thing as capable as it is for the work it does; i.e suspension kit, hd power steering pump, optima battery, tranny cooler, oil cooler, aluminum rad, tw driveshaft and synthetic oils all the time every time. Also, because my t-case and tranny take a beating from the snow plowing, I change out those fluids every season with good synthetics to ensure long life. You always need to equip your rig specifically for the conditions it is exposed to, the type of work it will be doing and always look for the factory weak points and address them. If all that is done, your rig will always be reliable regardless of the conditions.