I have an 09 Jeep Liberty with 77k miles and a 08 Ford Focus with 60k miles. Can I switch them over to synthetic oil or do they have too many miles on them?
What is the oil consumption like for the 2 vehicles and do you have any oil leaks? If you are burning oil or have any leaks it's best to switch to an HM oil, but if your oil consumption is normal and you have no leaks, changing to a full synthetic is not a problem.
Originally Posted By: stephen9666
The "too many miles for synthetic" argument is an old wives' tale. Use synthetic with confidence.
Yep, I had to explain this to my girlfriend the other day, along with the 'once you switch to synthetic you can never switch back' myth. Was probably true at one time, but not with modern synthetic oils.
Oddly enough several oil companies like Royal Purple and Amsoil do warn you about the consequences of changing to a full synthetic for an engine in poor condition, this is on one of the Amsoil sites: Petroleum motor oils are notorious for forming what’s know as a “false seal”
Varnish and crud will build up around a failing seal and help keep a
more viscous petroleum oil from leaking. Synthetic oils that are highly
detergent will clean off the build up and expose the all ready failing
seal. There’s your leak!
I don't see a problem going synthetic at 77,000 miles. Does the engine have seepage at the seals? If not, go for the synthetic. You also could go the high mileage route with Maxlife Synthetic or Maxlife Nextgen Synthetic.
My 05 ram got nothing but bulk oil from the dodge dealer until I got it 20000kms ago. Since then I've used pp AFE,and eneos mixed with m1 0w-40. Truck has almost 260000 on it right now and not even a hint of a leak.
Some syns long ago would expose an inadequate gasket because they were true group 4 syns and didn't have any additives to help gaskets. That is no longer the case. You can switch back and forth any time you wish.
If that wasn't the case how an we adequately explain syn blends and using them.