I've been running Mobil 1 5W-20 with a pure one sice I got the car 20k and a year ago with 5k OCIs. Never had a problem with it starting cold, but I'm wondering if it might be beneficial to switch to Mobil 1 0W-20 with the next change (within a week). Using the search I could not find any specific info to the F23A1 engine. Thanks!

 

Switching to 0W-20 will definitely be beneficial for your engine, even on a hot summer day. The thing is, 0W-20 flows better than 5W-20 at all ambient temperatures found pretty much anywhere in the world, and the better the flow when "cold", the quicker oil is up in the engine protecting the individual components. How much better? Not much when the OAT is over 100 °F, but if you live in an area which sees winter temperatures below 40 °F, then there is a very measurable difference, and that difference continues to grow as the OAT drops even further.

FWIW, we recently purchased a 2001 Accord V6 and I switched it to 0W-20 Mobil 1 at the first oil change. We've recently had a few mornings down near 20 °F and the engine cranks with the same vigor as it did back when the OAT was over 90 °F.

 

JetHead, you live in Alabama, warmer than most places in the USA.

Suggest, before you change, stop by your dealership and
ask the service guy what weight/type oil they use for your year car.

 

JetHead's car comes with a recommendation from Honda of 5W-20 which by definition means that 0W-20 is also recommended.