Speaking of oil prices: Yes, Honda oil is pretty expensive. I've ridden a Honda motorcycle for years. The dealer wanted $4.99-$6.99 per quart for GN-4 (motorcycle oil. So, instead of using the Honda oil, I've been using Mobil 1 in my bike for several years now. If I recall correctly, Target had the quart bottles for $3.75 the last time I changed my oil. I'll have to look the next time I'm there.

 

I tried changing conventional oil at 5k once (and I did a lot of city driving back then), it came out like cambell's chunky soup. My engine purred after that too. My guage ever since has been if the engine can tell it got new oil then I waited too long. Optimum changeout using this totally unscientific measurement is about 3k for conventional oil and 4-5k for synthetic given my driving conditions.

For more scientific info try:

http://www.blackstone-labs.com/articles.html

Much easier is to assume the severe schedule and use M1 and you will be fine. Unless you are nearly pure highway you are not really qualified for the manufacturers "normal driving conditions" maintenance schedule, at least that is they way I always heard it.

 

I use to use Honda 0W-20 (could get the stuff at dealer cost) for the 0-5K, 10-15K, 15-20K, 20-30K intervals (also used Honda's oil filter). In all cases the oil came out looking very good (even in the last interval of 10K), in fact it was always hard to read the level on the dip stick. The one thing that this car does very well is not burn oil. I know all cars burn oil but this one seems to do it without seeing a difference on the dip stick.

Anyway, I switched to Mobil 1 0W-20 at 30K (along with a M1-110 Mobil oil filter)... and have changed it every 10K miles. The oil reading on the dip stick is still very hard to read because the oil is so clear. When the oil is replaced, it still looks really good. In both regular and synthetic changes, the oil has always looked good. So that's why I go with the 10K oil intervals. If I did more city driving I would probably switch back to 5K.