Synthetic Oil?

No reason not to. In any case put in no more than 3.5 US quarts; in fact 3 quarts even is fine.

I changed to synthetic at 15K, unsure whether there was still some breaking in to do that the synthetic might have interfered with. I still don't know, and would wait until 15K again if I had it to do over. But you're probably okay at 5K.

Mike

I put some Mobile 1 (5-30w) in at 1500 miles. I don't like the idea of any metal shavings from machining being encapsulated and hiding in the oil channels somewhere to wreak havoc later. Most of the other vehicles I've owned (motorcycles) had the 600 mile service for that reason along with some bolt and valve train adjusting.

However, at 5K the dealer did the job and put in Havoline 5-30 (reg. dino oil). Then they stuck on a sticker to bring it back at 8K miles instead of

10K. I doubt if 3K changes are going to extend the life anymore than I will own the car before replacement in 7-8 years.

I'm about to roll on the 10K so I may change it myself and go back to Mobil

1. If for anything, just to keep dino oil varnish down as I really dislike seeing the stuff inside an engine and trying to clean it out.

B~

If any metal shavings large enough to matter are not getting trapped by the filter then the filter is defective.

Ditto that. Follow the schedule given in the maintenance guide that came with the Prius. Anything more just helps the dealer with his boat payment.

The '04 owner's manual advises not to change back and forth between fossil and synthetic oils. I buy bottled oil (Mobil 1) and give it to the tech to use.

Does your dealer discount the oil change accordingly or do you end up paying for the dino oil?

If you ever pull an engine apart you'll see all kinds of stuff in there the filter didn't catch. Some engines, trannys, and rear ends even have magnets on the drain plugs and you see all kinds of metal on them. Toyota was known for sludge pockets in their engines if you've been around them long enough.

Besides, the input screen to the oil pump filter usually keeps most of the larger debris from ever hitting the filter. It's just good insurance.

B~

Toyota of RIchardson, bless 'em, does not charge me for the oil. $16.95 to do the work.

Thanks, Richard, I'll see what my dealer says.