There are "reports" out there that advise not switching to synthetic in higher mileage vehicles and others that say it's not such a big deal cause filter tech has changed, but what year did it change? To me HIGH mileage is over 150K not under 100K.

I'm thinking about switching to full synthetic (possibly AMS, IDK) but I don't need any seals leaking in any of the 3 cars in the driveway. 98 Ram 1500 169K, 99 Crapstar 115K, 94 Saturn SC2 225K.

I'm not sure about syn in the sc2....it burns (or drips) about a 3/4 qt every 6K. If it does have a seal that is starting to fail I'd rather not help it out, if it's dripping I don't need it dripping any faster.

Should I stick with the MaxLife or can you ease into synthetic? If the seals do start to lead are you SOL or can you back to a high mileage oil and maybe re-gum up what you just un-gummed?

Thanks much.

 

Just try a synthetic blended oil, it has some of the properties of the full syn and conventional and is about half the price as syn.

 

This was long ago debunked. Synthetics are better, period. If your vehicle already leaks it may leak a little more, but synthetic oil won't cause an engine to suddenly start leaking. Use a synth blend if you want to save some money.

 

What was debunked? syn causes leaks or that syn is better? Or both? The last time I looked into synthetics was way back in 2000'ish. But then I was on another site and all their ASE cert mechs said "synthetic was no better, just cost more" So I left it at that. I've started to "slowly" come around to the lighter side.

I'm not looking to save all that much on an oil change, but better performance and decent longevity.

 

That synthetic causes leaks. Like I said, if you have an engine that is already leaking it may leak more with synthetics because of the superior flow characteristics. But it does not do anything to the seals to actually cause leaks where there were none. I've been using full synthetics in my vehicles for years with no issues. That includes my Ram, my Jeeps, my Harley and my dirt bikes.

 

I'm only gonna speak on my experience and research. I switch to full synthetic at 140k. So what happened? My rear main seal started to leak like a sieve. SYNTHETIC OIL IS NOT BAD NOR WILL IT CAUSE ANY GIVEN GASKETS/SEALS TO LEAK. What happens is that synthetic oil is so good at wicking and cleaning out your engine, that it exposes bad seals that weren't leaking due to being blocked by sludge and gunk. This won't happen to everyone. Some people have no problem with synthetic, others do. There's only one way to find out.

 

I went from heavier 20-50 oil in my air cooled vw to synthetic 5-30 and it started pouring out of my engine everywhere....but I agree better flow characteristics along with being thinner caused this as far as Im concerned...I replaced my gaskets and it helped a lot but I couldnt stop it from leaking on my spring loaded push rod tubes so I went with a synthetic blend 10-30 when adding a remote oil filter setup and it helped tremendously...(plus the older engines require higher zinc levels and such than the synthetic had for cam and rocker wear.) newer motor oil is bad to use without the proper additives for most engines from the 70's and older...the api service code distinguishes whats in it..
I also switched from full synthetic in my old vette to the valvoline high mileage conventional (blend?) stuff and the additive they put in it to swell the seals works because it stopped the small leak and also doesn't burn as much oil....(I didnt even add the restore or lucas stuff I usually do.

 

Yeah, same here. I switched back to Valvoline high mileage.

 

i put full syn in my truck about a year ago, with 115K and no leaks

 

usally that high mileage stuff is a synthetic blend anyways