Sythetic or regular - Page 2 - Toyota Nation Forum : Toyota Car and Truck Forums

Idealconcepts · 03-10-2005, 12:55 PM

Is there any truth to the oil leaking after changing over to synthetic?

GregoryM · 03-10-2005, 02:29 PM

There are exceptions to everything but, yes, in general, leaks tend to be exacerbated by changing to synthetics.

d1live · 03-10-2005, 11:03 PM

Quote:

Originally Posted by Idealconcepts

Is there any truth to the oil leaking after changing over to synthetic?

No, I have been using Mobile1 Super Syn for years now in my truck, power washers, lawnmowers, motorcycles, no leaks. Had a 97' Yamaha YZF1000 that used oil using Yamalube, then I switched it to Mobile 1 Super Syn, oil consumtion was cut in down to almost none and the bike ran smoother. I now have about 600 miles on my 2005 Tacoma Prerunner 2.7L and in 400 more miles Iam switching to the Mobile1 SS, wouldnt hurt to change now but weather sucks here right now and nothing wrong with oil thats in it I just dont trust conventional oil to 5000 miles. Ill change at 1000 miles or so and then again at 5000, 10000, 15000 ect,,... Also changing 5-speed tranny oil and rear diff. oil to Royal Purple synthetic 75-90W gear oil (good stuff). Maybe it helps, maybe not but Ill sleep better knowing my truck is in tip top shape for many years to come.

fadetoblack72 · 03-11-2005, 04:54 AM

I heard that you aren't supposed to use synthetics in the tranny because they are too slipperry?

d1live · 03-11-2005, 08:55 AM

Quote:

Originally Posted by fadetoblack72

I heard that you aren't supposed to use synthetics in the tranny because they are too slipperry?

Their are many myths about sythetic oils, but most are just that,. myths. Some carmakers are using sythetics in everything, engine, tranny, Rear diff, no problems with anything. Main reason Toyota dont use it is cost, I just bought 3 gallons of Mobile1 Super Syn at $18.99 a gallon, enought for 2 changes 1000 miles and then 5000. I figured it will cost about $12 more every 10000miles and cut out one change, I wouldnt run conventional oil for more than 3000 miles, it usually starts looking bad around then. Theirs the kicker, 2 oil changes every 10000 just like the Toyota manual sez, or 3 oil changes using conventional oil. It wont hurt anything and its piece of mind for me, better oil means better protection and less wear. Just my 2cents worth. Thanks

bigjohn · 03-11-2005, 09:02 AM

As far as leaks, sometimes syn does make leaks worse. The mechanics of this i believe is it cleans extremely well, cleaning away crud around the seals, that was helping the seal retain oil. As far as syn in transmissions one thing I have learned is most syns are gl5 rated, you absolutely cannot use gl5 rated oil in a transmission calling for gl4. The pressure additives used in gl5 will attack and dissolve bronze which was used as bushings, etc in older tranny's.

Idealconcepts · 03-11-2005, 10:07 AM

Glad I asked all these questions, like some mentioned earlier in the thread this is a hot topic and I am sure it is providing alot of people with good information. Atleast I know I am going to go with synthetic on my weekend car, the pizza getter (a.k.a 2000 Type R)

bigjohn · 03-11-2005, 11:53 AM

One more thing about oil usage and synthetics, I started using synthetic in an ancient tractor that I have. 1948 to be exact. Bad seals, bad rings, bad everything but still running. I never could notice any additional oil leakage from the seals, but I did notice overall decreased oil consumption. It burnt and smoked oil like crazy. Synthetics do not "burn off" as fast as conventionals.

2tacomas · 03-11-2005, 12:36 PM

Quote:

Originally Posted by bigjohn

One more thing about oil usage and synthetics, I started using synthetic in an ancient tractor that I have. 1948 to be exact. Bad seals, bad rings, bad everything but still running. I never could notice any additional oil leakage from the seals, but I did notice overall decreased oil consumption. It burnt and smoked oil like crazy. Synthetics do not "burn off" as fast as conventionals.

Synthetics have a much higher flash point compaired to regular non-synthetic oils.

mattunique · 03-11-2005, 12:42 PM

I just switched over to Mobil 1 for my engine oil on my 2004 Taco 6cyl Xtracab (10,000 miles). My ASE mechanic called Toyota to ask about using synthetic in the tranny and transfer case and they said they don't know if it is OK to use or not. Of course this means if I were to change I would void my warranty.

I wanted to switch to synthetic to help with heat dissapation since I tow a boat. My mechanic recommended the synthetic over a tranny cooler unless I were towing right at the max capacity.

Bottom line it seems impossible to find out the scoop. Toyota does not sell any synthetic oils so of course they would not recommend it for their vehicles. My mechanic called Mobil and they verified their product would be fine as a replacement for the Toyota tranny fluid. Of course they would be inclined to say that.

--Matt

crazycruzer · 03-11-2005, 05:53 PM

Quote:

Originally Posted by fadetoblack72

I heard that you aren't supposed to use synthetics in the tranny because they are too slipperry?

You should try B&M or Royal Purple. Shifting is so much smoother.

crazycruzer · 03-11-2005, 05:55 PM

I have a 2002 BMW 325ci and the manual and oil cap states that Castrol Syntec is recommended. I switched over from Mobil 1 to Castrol and like it a lot better! I'm not sure how the new Mobil 1 with 5000/10000/15000 but would like some opinions from those who have tried.

qsd-dan · 03-13-2005, 02:53 AM

Well, I guess I can be a testimony on leaks after switching to synthestic on my honda accord. Several months ago I changed from castrol to mobile one and now I have a leaky rear main seal

and with only 61,000 miles

As for my toyota, I changed the diff, trans, and motor to synth after 19 years and 160,000 miles and not a drop of anything. I guess toyota is the sh$t when it comes to their gaskets