NEVER exceed the manufacturers recomendations for oil changes. Honda says 3750 for severe use or 7500 for normal use for the Prelude. If you exceed these limits, Honda can deny any warranty claim you may have if you have an internal engine problem.

That said, as I mentioned in earlier post, it is BETTER to use 5w-30 full synthetic than to worry about Honda's recommendation and stick to 5w-20 oil IF NO 5W-20 synthetic is available in the brand you use. I use Mobil 1 full synthetic. It's about $4.00 per quart and is good enough. Amsoil and Royal Purple are more expensive and not as readialy (sp?) available as Mobil 1. Now, some of the German manufacturers use synthetic from the factory, and they have monitors that count # of engine starts, and thus tell you when to change your oil depending on the number of cold starts you have had since last oil change. They extend the oil change interval in this way to over 10-15K miles.

But NEVER exceed what the manufacturer says about the oil change intervals.