I am getting close to first motor oil chg. It appearsto me that Honda may have specified 5W20 more for fuel economy that for engine reliability. So does anyone have experience or even opinion on using something along lines of Mobil 1 5W30 or even 0W30. Since I already get very good mileage I would be willing to sacrifice some mileage for improved reliability. Temperature range is from freezing to very hot. Thanks.

 

I have good answer to my question. The rec'm motor oil for new Civic Si is 5W30 for all temperaturesor even 10W30 for temperatures above 20 deg F. I believe that Honda specified 5W20 in EX primarily for milage benefits and I believe that either 5W30 or 10W30 would give better protection. So for my climate zone I will be running 5W30 in winter and 10W30 in summer. I will begin using full synthetic at 10,000 miles.

 

I would say you're fine with the 5w-20. Honda tends to know what they're doing! Keep in mind the Si revs much higher also, and is designed for more spirted driving. It's a pretty different motor, so I really wouldn't compare them. What is your concern with the 5w-20? I have never seen any evidence that shows it to be a problem. Just keep with regular changes (3-5k) and you'll be fine. My mom's Civic runs on 5w-20 and loves it...ran 10w30 a few times and the change back to the reccomended was very noticeable in better throttle reponse.