Hi all...this is my first post and I have to say there is a wealth on information coming from y'all! My question is is it too late to switch to synthetic oil? My 88 has 267K and my 91 has 114K. I know there are good benefits to synthetic, just wondering if I might cause problems with the mileage I already have. Also what about the other lubricants? Can I go synthetic?
Thanks for all the info guys! Hope I can contribute some also as I've been a Yota truck owner for the past 14 years.
Chuck

 

I run sythentic in both my '86 and '92 4rnr's. I first learned about synth fluids when my wife had '78 Plymouth Trailduster 4x4...like a Dodge Ram. I've never had any issues with it. Someone told me the seals would leak....some said it would recondition them. So, I read bobistheoilguy.com (might check that site out!) and found there shouldn't be any issues as long as the seals are actually good in the first place, just might need to run a heavier weight for tolerance wear. If the seals leak, they were going to anyway. I have 208k/mi + on my '86...I run 15w-50 M1....no problems. The '92 has just been rebuilt...so no judging by that. And the Plymouth is gone...sold...but no issues before that with 170k/mi + !!

 

Oh yeah baby, run that stuff in everything, gear oils too. Can be good and spendy, but worth every penny in my book. That being the pure synth., the mixes aren't as good, but better the the non in every way. I run my tuck with intent on breakin' things. This stuff makes that job more tiresome.
I believe what MMA Alex might be tryin' to tell ya is you'll be burning some of that oil as sneaks into the comb. chamb. THE ONE "DRAWBACK", if that's what it must be called.

 

try it, and just watch the oil level.

semi synth is way overpriced, and only contains up to 30% synth, and the rest is dino. Spend the extra $1/quart and get synth.

 

I switched to full synth at 150k. I have no idea how what PO used, but he dod little maintenance. It leaked oil before the switch, seems to leak a little less after the switch. I bought the synth when it was the same price as regular oil (sale) otherwise I wouldn't have bothered.

 

I am one of the rare few who have experienced leaks when switching to synthetic. I made the switch at about 85k and all seemed well. I was making the drive from L.A. to Reno in the summer heat (100+ degrees), and on a steady highway climb, I noticed smoke coming out of the rear of the truck.

I pulled 'er over and oil was leaking out of the rear main seal at an alarming rate. I made it home. I switched back to dino, and she never leaked again.

 

if i had the 20 bucks for syn i would buy it

 

For the sake of discussion, I've read both sides of the din vs. synth coin...an argument that will probably last for eons...so I won't try and persuade anyone either way.

IIRC, chickenlover, that phenomena is "supposedly" because the dino has a way of forming deposits that will do that...."plug" leaky seals. Dino is constructed of non-uniform molecules that create a tendency to sludge. While synth has uniform molecules and will not do that. Just out of curiosity, what weight oil of synth did you use? And what weight dino do you use? I'm just wondering if that makes any difference or not. One of the reasons I started using synth was it's ability to keep moving parts cooler...better heat transference=better lube....and it will not sludge. On the other hand, an Amsoil dealer once told me whatever oil one uses filtration is the most important thing. So, I installed a second oil filter...remote bypass. Even if I did use dino in my motor, I would still use synth in everything else, though.

In the interest of dino swearby'ers, Schaeffer makes a good dino....from what I read.

 

filtration is very important. I switched to synth so that I could go to school, and not worry about oil changes while im at school because I like to do them myself, and just dont have a place to do em. The synth keeps from oxidizing for a lot longer than dino. If you pay attention to the oil it will be in a lot better shape when you do change it.

I like to change the filter every 3-4k miles because once the filter plugs up the oil just bypasses the filter, and thats when you run into issues.

 

Without coloring the thread any further with an opinion about synthetic, the answer to the original question is that it is most definitely ok to switch at any mileage. If you need reassurance search google for "synthetic oil myths" and read all the information that comes up.

 

Its not so much that you cant run synthetic after a certain milage, but if you truck burns/leaks dino oil it will leak/burn more with synthetic.
If your truck doesnt burn or leak oil, go for and and just watch the oil level.

 

I ran synthetic in my 87 toyota for the last 150k that it was around. It died at 280k. I found no problems with changing to synthetic that far into the life of the motor. I never had any leakage problems. Knocking also stoped at cold starts (as cold as san diego gets anyway.)

 

i wasnt sure i wanted to jump straight in to full synth @90k, so i used a synth-blend first, then full synth at the next change.
126k now & no issues at all.

 

i run synthetic in my 4runner with 140k (started at 137k) and my honda accord with 165 (started at 140k)

the honda leaks, and bad, but it did that way before i started using synth. the only reason i do is so i can increase the mileage between oil changes since i hate working on that car.

 

Old thread but,

I have 248,000 miles and i was told it would be fine to switch to synthetic. I was told it would actually be better.

AFAIK, there is no leaks, and not alot, if any burning.

Take it this way, within the 3000 mile oil change period with castrol conventional, i never have to add more oil.

So my question is would it/should it be okay to switch to lets say a mobil 1 full synthetic oil?

Also, you guys said if it leaks then switch back, and i heard you couldn't switch back after going with synthetic, is that true?

I will continue to do research on the matter! No harm in asking right?

 

Mobil-1 is completely compatible with other oil, you can switch back & forth. Synthetic will not cause a leak, if you have a leak it might get worse i.m.e. but not "OH MY DEAR GOD" worse. I have heard people say synthetics burn off too but I've been using it since it was commercially available & I haven't had any issues at all.

One note I think is worth mention; in it's early years of development fully synthetic oils would break down rubber & pit metal if used for long periods of time & they were not compatible with regular oils according to what I read. We're talking really early development here as well, like 40's & 50's era Nazi Germany; soldiers came back talking about how poorly their synthetic rubber & diesel fuel was made. It went a long way by the late 60's & early 70's most (not all) of the problems had been eliminated but I think that's where a lot of this rumor mill got started. Modern synthetics are better in every respect than conventional oil.

 

It wont hurt to swap over
1. Get a UOA on the oil your runnin now
2.Run a flush before putting new synthetics in.
3. Change your oil
4. Get some milage on it and get UOA done on the synthetic oil
5. Doing a UOA is the only way to tell if your oil is doing its job, it also picks up on early problems such as antifreeze in the oil. It will also show you which metals are wering and how much.
6.Doing UOA from time to time will tell you exactly whats going on.

 

Conventional ftw.

 

What is a UOA?

 

Used Oil Analisys. A test of your current or used oil. You can suck it thru the dipstck or get it while your oil is draining at the time of a change. Its the only way to now what your oil and your engine are doing.