By Scott A. Keen (Scottkeen) on Thursday, July 12, 2001 - 05:31 pm: Edit

I was told by a friend that it's a bad idea to switch to synthetic oil (Mobil 1) once you've been using regular oil. He said that switching may cause leaks because the synthetic stuff is much slicker and your gaskets are conditioned for the less-slick regular oil.

Is this true? I have 58K miles on my 97 Disco. It's been on regular oil, as far as I know, and I was thinking of getting the oil changed yesterday with Mobil 1 synthetic.

By Axel Haakonsen (Axel) on Friday, July 13, 2001 - 03:35 am: Edit

Synthetic oil will not cause a leak. Because of its viscosity it may seep through where regular oil didn't, but that just means the leak was there to begin with.
Now think about how that translates to lubrication of your engine....

By jason mack on Friday, July 13, 2001 - 04:57 am: Edit

I love synthetic oil! Regular motor oil has a property to it that makes it get absorbed somewhat by seals and causes them to swell. Synthetic doesn't do this, so shortly after you add synthetic you will probably spring a rear main leak. I fix this by adding a half can of seal conditioning stop leak. I think last time I used prestone brand.
A couple years ago I switched both of my jeeps to full synthetic on the same day. One had 36000 miles and the other less than 1000. They both started leaking at the same time! Both had different engines and both leaked from the rear main. I split a can of stop leak between them and it went away. I have heard that amsoil full synthetic has an additive that will swell up seals and stop leaking, but I have not tried it myself. Despite the leaking I think the switch is worth it and I continue to use it in all my vehicles

By Scott A. Keen (Scottkeen) on Friday, July 13, 2001 - 06:56 am: Edit

OK, thanks for the info.

Anyone tried the STP Engine Stop Leak additive? Is it compatible with synthetic oil?

(I went to the Prestone website and couldn't find any stop leak there)

By Daniel on Tuesday, July 31, 2001 - 04:00 am: Edit

Something I have heard about switching to synthetics is that you cannot go back to regular oil after making the switch. Is this true? If so, why?

By Steve (Steve2) on Tuesday, July 31, 2001 - 06:46 am: Edit

as far as i know as long as the regular oil is compatable with synthetics (as most are) - you'll be jsut fine. i found the car runs much smoother with synthetic - and seems to spoll up easier in a 3rd gear boot on the fwy. i also recommend castrol syntec 10w30 over the mobil one - as it is even nicer than the m1.

steve

By chuanchen on Tuesday, July 31, 2001 - 12:14 pm: Edit

I switched to synthetic (castrol syntec 10w-30) at 21k on my 99' Disco II. it came out just great!! the engine running significantly smoother and noticeable more gas-efficient.(improved from 15 to 16-17 mpg) no leaks found.

chuanchen

By mike w on Tuesday, July 31, 2001 - 12:29 pm: Edit

what about semi-synthetic blends...any opinions.....

By rose (Rose) on Wednesday, August 01, 2001 - 03:53 pm: Edit

Scott, your "friend" doesnt know dick. Switch to synth., I highly recommend Mobil 1 15w -50 for the LR's and dont listen to Daniel, he's a moron to think that he can't go back to regular oil.

By whocares on Wednesday, August 01, 2001 - 06:56 pm: Edit

hehe, your rite about daniel..Putz

Kinda like saying, once you have diet coke with nutra sweet, you cant go back to regular sugar
or
Kinda like saying, once you drink homogonised (sp?)orange juice, you cant go back to drinking strait from the juicer
or
Kinda like saying, once you use synthetic oil, you cant go back to "real" oil

By hello on Thursday, August 02, 2001 - 03:10 am: Edit

daniel was asking a question - not making a statement

By Daniel on Thursday, August 02, 2001 - 04:05 am: Edit

Well now, don't we have a couple real winners here. If you two loosers ("whocares" and "rose" I mean you) had taken the time to READ my message you would have realized that it was indeed a QUESTION. If you have been posting here for any length of time, you would also know that I have recently gotten involved with this make and model. This explains why I have been posting what might be ridiculously simple questions to some. However, I have been very upfront about my lack of experience, and very appreciative to the better posters on this board for their help. In the future why don't you two pay attention to what you're responding to.

By Simon on Thursday, August 02, 2001 - 05:49 am: Edit

hehehe
dont you love the flames?

now Daniel are you the ft. lauderdale Daniel?

Simon

By Daniel on Thursday, August 02, 2001 - 06:31 am: Edit

No, I'm in Chicago and I do love the wise guys. It keeps things lively, but these guys just didn't pay attention to what I actually typed.
It was an honest question...albeit from a newbie. So shoot me.

By rose (Rose) on Thursday, August 02, 2001 - 07:08 am: Edit

Dannyboy, I'm sorry.. Now quit youre moaning and take a little critisism like a man.

By Daniel on Thursday, August 02, 2001 - 07:43 am: Edit

Thank you Rose.
Now I feel all better. In the future, I promise to not be so sensitive.
Sincerely,
Daniel