I want to know what the outcome of peoples switches from regular to synthetic after 100,000 or more miles.

 

Just use conventional oil, your car will still last over 200,000 miles.

 

If you can afford it.
Flush it & run synthetic.
If you can't afford it.
Flush it & run good dino.
If you can't afford that.
Flush it & run oil.

Pattern developing.


Dude, if your engine has 100,000m on it. I got $20 says it's leaking now regardless of what oil you use LoL!
Rubber only lasts so long man. ;0) And your rubber mounts & bushings are probably shot too!
time > rubber

 

I used Mobil 1 since the first time I changed my oil, and I never really had any oil leaks. The only oil leak that I had was the rear valve cover gasket, which could have been a sign of old age.
I didn't vote since I don't meet any of the options in the poll.
I have ~145 miles on it now.

 

I have 140,000 no leaks. Then again I just had the engine rebuilt at 130,000.
Good time to use synthetic?

 

When I had my '01 ES, I got the rear main seal fixed at the 90K service, and I believe I switched to synthetic right after that service. Did not have any leaking oil problems from the gasket or anywhere. Sometimes the synthetic oil would not burn a drop during an oil change interval.

 

I switched around 75K miles to Mobile 1.
No leaks until I used the Mobile 1 15K mile interval oil. Mileage was around 185K when it started leaking.
I stopped using that after only 1 use.
I've had to pay $800 so far to replace a few seals. I have one more that needs to be changed.
Car has 219K on it now and I am still using Mobil 1.

My advise, stick to one type of oil and change every 3k-4k miles.

 

Oceanview; my guess is that the 185K miles had at least as much to do with the leakage as the change interval. That said, I wouldn't go more than 7500 miles or 1 year. I also use Mobil 1 and will never use anything other than a good full synthetic. I don't believe this includes Castrol Syntec, which I used to use. This is based on a lot of reading I've done regarding oil technology and testing. One word of caution, don't use synthetic racing oil; it doesn't contain detergent additives and is not suitable for long term use. Oil in racing engines is changed VERY often.

To the skeptics regarding whether using synthetic oil is "necessary": Synthetic oil has been proven to be superior to regular oil in just about every measurable way and does result in reduced engine wear. Also, synthetic oil is much more resistant to sludging. This is especially applicable to many Toyota engines, including the 3 liter V6 in the ES, which are particularly susceptible to sludging. If you care about your car and want the engine to last as long as possible, how can anything less than full synthetic oil be good enough? I pay about $14 more for a 5 quart jug of Mobil 1 than I would pay for regular oil. When a tank of gas costs about $35, $14 sounds like very cheap insurance.

One last thought: I wonder why anyone would buy synthetic blend. If you believe synthetic oil is worth using, why degrade it with regular oil? Also, who knows what percentage is synthetic versus regular oil? It sounds like a marketing gimmick.

 

I agree with you 100%.
I only use Mobil 1 Synthetic as it is the best as far as I am concerned.
I use it on my Mercedes Benz as well and the engine feels and sounds just like new.

I have been changing the oil every 6000 - 7500 miles with the mobil 1 and its just fine. The cost is about the same as doing oil and filter changes every 3,000 miles.

 

Longer intervals is OK if it's clean. But the big thing is recognizing that you still need to change the filter & top-off at 7,500 miles for the filter's sake.

You could always spin on one of the 1, 1 1/2 quart monstor oil filters too.
1fz-fe, and the 2uz-fe v8 use them. The newer fse head GR blocks use pretty large filters also. Toyota filters all spin on, but you just have to check that the seal is in the right place.


The more oil you carry, the longer it lasts. Just like filters only last for so long.











In the US to be a synthetic blend it has to be 25% synthetic.
It's not uncommon for people to blend their own oils together.

 

wanted to switch to synth ( its a lex, but of course) when i got my 97 es 3, but after reading posts on here concering problems and leaking issues after switching to synth on higher mileage cars, i decided against it. i currently have 158K+ and backed off the synth tirade i was on after reviewing what some have said here. i just recently replaced both valve and rear main seal gaskets and was wondering, would i be ok to switch now? or if it aint broke, dont fix it?

 

That's a personal choice, knowing what I know, I would have switched earlier and kept with sysnthetic.

 

I'm with vin on this one

 

yea, i started putting synthetics in around 13x,xxx and i havent had any problem yet. ::crosses fingers:: right now im at 172,xxx miles and its been about a year.
Goodluck
Charley

 

This is discussed in legend forums for a long time. Basically if your engine's running fine just keep using dino oil. Or better yet try high mileage oil like valvoline maxlife. I've been using it for awhile on my 91 legend. Now it's at 191,XXX miles and no smoke, and burns no oil. Runs like a champ. Only reason I'd switch to synthetic is if I have a high performance engine under 70K miles. I actually used amsoil systhetic on my other legend. Although I noticed smoother engine I switched at high miles(120K miles). About a yr later my oil started to seep through gaskets. just my 2 cents. There's that saying 'don't fix it if it's not broken' did I say it right?