Years ago I had a '75 Ford van with a 351W engine and 150K miles on it. An Amsoil dealer convinced me to switch to synthetic oil and their system of two oil filters. Within a week, the oil pressure dropped to zero at idle, with bearing knock, and it took a full city block of travel to bring the pressure up to 40#. Evidently, the synthetic oil cleaned the internals of the engine and ran all that sludge through the bearings and wiped them out.
The next Ford van used synthetic oil from the start and after 150K miles, it developed emission problems which were never able to be fixed.
Now, I have a 2007 van with 85K miles and only drive it about 2500 miles a year, usually 3 miles a day. I’d be interested to switch it to synthetic oil, but am afraid the same thing will happen.
What’s your advice about switching to synthetic oil once the engine has some miles on it?
I’ve done this several times with used vehicles. A Ford van I got with 60K, a Suburban with 96K, a Mustang with 10K and one with 50K.
The Suburban was the worst. Synthetic washed so much junk out of the engine (it had Quaker State stickers all over the door) I had to change it at 2000 miles plus it used a 2 quarts in that time. The oil consumption dropped to 1 quart in 2000 miles and I went 4000 on the oil change. The next was 1 quart in 4000 miles and I changed every 5K after that. I sold the truck at 118K.
None of the other cars or the Ford van had any such issues. Maybe a little higher oil consumption in the van for the first change. Not enough to matter.
I have one Chevy Avalanche I’ve owned since new running Mobil 1 that has 133K on now. The 5.3 V8 uses virtually no oil and runs like new. Spark plugs and wires are the only engine parts I’ve ever changed.
Your Amsoil 2-filters issue was the lack of an anti-drain-back check valve and the long time to re-fill the filters at startup. That starves the bearings. The Ford van problem is not an oil issue, it was an issue of your mechanics not being clever enough to fix it.
Given your short mileage and short trips, I’d switch to synthetic without hesitation. I’d think about changing it every 6 months because if you live in a climate with seasons. Change every year if you live in a warm-all-year climate since the moisture in the oil likely gets driven off.
I’m not sure if you’re saying the Suburban worked out well with washing the junk out of the engine or not. Did you think 2000 was the proper time to change filters, or you had the oil tested?
I live in PA with all 4 seasons. You seem to recommend that I switch to synthetic.
I had no problems with the Suburban after switching to synthetic. Just described the issues. I changed after 2000 miles because the engine oil looked very dirty.
I have synthetic fluids in everything I own and have for 30 years. I actually am not suggesting you switch, that is for you to decide. Given your 2500 mile use, and living in PA, I would suggest you change it twice a year just for the moisture. From that, I might actually suggest you stay with regular oil.