"Teredo" wrote
Recently had the plugs changed, first time since new. Compression test
each cyl. All 6 (4.2L inline 6 Vortec 275 HP 10:1 compression ratio)
were within factory specs. Also use a Fram high density filter.
Oil pressure is 41 PSI at hot idle, 70 PSI at 2k rpm. The motor is so
quiet it's hard to tell if it's running. The factory 'change engine oil'
light comes on each 5k miles after reset. As far as I'm concerned that 3k
oil change rule is worth following.



Why?
My Buick was the same way, except I changed oil at 7500. In the 130,000
miles I had the car that would be 17 oil changes. Following your method,
I'd had had the oil changed 43 times and the results are the same. At $30 a
pop, I'm $780 ahead.

I imagine I could have kept it longer, but the car had other issues and I
gave it away to may grandson. Damned engine ran perfect though.

I've also owned a couple of Sonatas. The dealer (I don't use dealer service
in general) recommends fuel injection service every year for $129. If I did
that on all my fuel injected cars in the past say, 20 years, I've have spent
thousands of needless dollars. I've never had an FI problem. So, 2 cars at
$129 for 20 years, the shop would have $5100 of my money and I'd have no
gain.

Preventative maintenance is important, but should be done with sensibility.