96 GL V-6, 37K. we drive only 3,700 miles a year and change oil every 3K. I heard I am looking for sludge to build up in the engine and will have to replace the engine. Mostly short trips of course.

What say you?

 

Whats the average 'short trip'?

Short,, as the engine never heats up to normal operating temps? Long idle times/cold temps?Stop/go traffic? Engines now run 'much' cleaner than years ago, and at higher operating temps, and the amount of fuel/carbon deposited into the oil is much lower, or as carbon build up..Not unheard of though, and sludge can occur/form in many different ways or from chemical reactions, Heat, Condensation, Fuel (combustion by products) Soot, or what’s known as ‘Soot loading’ which gels or thickens the oil by means of the engine blow by are all contributors, or can even polymerize to a solid form to name a few possibilities, and/or even form from just not enough regular changes, load conditions, driving habits ect.. Although a better situation would probably be more use, longer trips, but with 'regular' serviceswith quality oils (no substandard bargain oils) and an occasional good hard drive, sludge shouldn't be a huge issue.. Synthetics may be a better choice for lube oil as it doesn’t suffer from the same conditions as dino oils in most cases.. Or oils with a dispersant additive for sludge control.. My brother drives a newer Toyota Camry at about the same mileages you reach, and only see's the open highway about once a month (if that).. I tell him to plan his trips/stops to extend the amount of 'run time' so that the engine can run at the optimal conditions for the times that its driven.. Hard to do sometimes.. But there are options to help control the causes of sludge if it’s a concern…

 

short trip a couple miles in Calif. Dr. trip is 6 miles one way, On the basis of what you say , we are o.k. as only Chevron oil is used at our lube joint and we do get on the freeway some times for a longer trip.