I have a 2012 Fusion with 2.5L i4 and 274,000 miles. It still does not burn a drop of oil, and never had a check engine light. I am wondering, do engines ever "wear out" without burning oil? or will they always burn oil as a sign that they are wearing out?
Yes. You've driven it conservatively, that's why you're not noticing oil consumption yet. The combustion chambers are sealed by piston rings, and if you drive like a maniac all the time (putting the pedal to the metal, causing the engine to go to high RPMs), your engine will go beyond its tolerance factor sooner. Once the piston rings start wearing out, you consume oil. The engine was designed to undergo several billion revolutions before deviating from said tolerances. Once that happens, your engine will start to consume oil.
@justin-shepherd i do not drive it conservatively, that car is regularly over 5000 rpm. but it's still kicking. i replaced the radiator recently that's about it. was thinking of getting the rod bearings replaced but used engines with 130k miles for that car at LKQ are $380 i think i'll just run it til it dies.
Is there something different about Saab's 2.3 Liter turbo fours
The Saab 2.3 is a very heavily-built engine. High-strength iron alloy block, forged internals, sodium-cooled exhaust valves, and more. The 2.3 in my Saab 9000 has been run well over 370,000 miles and still runs quite well. It doesn't burn oil, no need to add any between changes. (Though it does drip a little. British heritage.) That's not an outlier, it's common. The build was cheapened a bit with the advent of the GM-based 9-5 in 1999 but is still quite robust. Today's turbocharged engines are a completely different animal, light-duty and complex.
do engines ever "wear out" without burning oil
Of course they can. Oil control rings are just one wear point. For example, you can lose a main or rod bearing without having experienced oil burning problems.
My experience may be unusual, but I want to share in case it is of help to other members and possibly Scotty for his videos. I have a had two Saab 9-5 Aeros (2002 and 2005 with high-output 4 cylinder turbo engines) both a) with manual transmission and b) running Mobil 1 full synthetic 5W-30 High Mileage oil (changed every 5K miles after odometer read 100,000 miles). Neither burned oil at 270K and 290K miles respectively (I can always go the full 5K miles w/o topping up or low dipstick reading). I do a mix of 70% city/suburban and 30% highway driving, and I don't push my cars hard most of the time (except occasional high-speed passes or climbing mountains in Vermont). IMHO, Saab's extensive experience with turbocharging, use of the motor oil it was designed to use (there is a factory Mobil1 sticker under the hood), regular oil & filter changes plus not driving with a lead foot contribute to the lack of engine wear / oil consumption. It may also be possible that burning only Shell VPower (used by Saab in their endurance racing) may have contributed to durability / continued great gas mileage. Is there something different about Saab's 2.3 Liter turbo fours or are there general practices here that can help engines last longer before burning oil?
