15W is rated for cold cranking down to 4F. Mountain resort and high desert temps regularly get below 20F and I have no starting problems at all with 15W-40.
Dr.T is right. I stand corrected. It is 20W that is good to -15C (+4F).
[ October 01, 2003, 07:33 PM: Message edited by: Jimbo ]
quote:Originally posted by yankees1:
If nighttime temps get down to 40 and days at 60's will 15w-40 still allow proper starting/protection for a garaged car?
This will be my first time using 15w-40 in colder weather.
Well, started my truck up last night (about 45 degrees out) and I got "ticking" for about two seconds...after that, it did fine.
I'm currently using Delo, but I think I'm gonna try Delvac or Long-Life, and try a different filter as well (K&N?)
I just put 5W40 Redline in my Toyota and fall is here in force. It is going to get down to 27F tonight! I have no doubts that it will do fine this winter. It still has to meet 5W requirements. It seldom gets much colder then -20 for all but a few days.