2000 DTS - I changed the oil 16 months ago to 5W-30 Mobil One. I've driven it about 6,000 miles and the OLM shows 64% engine oil life remaining. All highway and suburban driving, in the AZ desert. So with 64% life remaining, why do I need to change the oil? I mean, it's not like there's fruit or milk in the oil that's going to go bad - it's just oil, right?
On my '97 ETC I changed the oil most recently at about 5,000 miles and 14 months, and the OLM showed about 20% life - that car has always indicated about a 7,500 mile oil life.
On my '97 ETC I changed the oil most recently at about 5,000 miles and 14 months, and the OLM showed about 20% life - that car has always indicated about a 7,500 mile oil life.