I'm already a Mobil 1 believer from previous cars but now I want to change my 55000 mile sc400 from normal to synthetic. I'd appreciate suggestions on what I should do.

Currently considering one of the following;

- Oil flush. What do they use when they do this?

- Change the oil run the engine a while and change again. (a little pricey)

These may not be necessary but you here all these warnings about mixing conventional and synthetic types.

Let me know, thx.

 

You're making this more complicated than it is. I changed to Pennzoil full synthetic about six months ago. Simply have them drain your regular weight oil and add the synthetic. DO NOT attempt to run out the old oil by idling your car with little to no oil in it. Changing the oil twice accomplishes nothing except draining your wallet of cash.

Peace

 

No, I meant do an oil change (putting oil in) and running it before changing it again. Was just concerned about the mixing of the two.

Then again, I guess they do have blends on the market now so it can;t be too bad for the engine.

 

This is what I did after my break-in period. I changed out the stock oil to Mobil 1 Tri synthetic, bought the oil at Pep Boys and took it to a local shop to do the change, now my engine need 6 bottles but I bought 7 with me.

After they drained the old oil out, I told them to put in 1 bottle of Mobil 1 and let it drain out, this will clean out the stock oils nicely, then they can put the new oil in. Yeah, you waste 1 bottle of oil at $5 but you clean out any dirty stuff along with it too.

 

Rumor has it that synthetic blend does not in anyway have the same chemical make up of full synthetic. Have any of you heard that switching to full synthetic will screw up the seals and stuff?

Humm, suppose I should do some reseach on this...

I will start some research on this and post again.

 

How do I change to synthetic lubricants?
For a mechanically sound engine with less than 60,000 miles, and which has been well maintained (i.e. regular and frequent changes of dinosaur (petroleum) oil), you simply drain out the old and add the new synthetic lubricant with a fresh filter.
For vehicles with more than 60,000 miles or one with a questionable maintenance background, you may wish to clean the engine with an engine flush before installing the new synthetic motor oil. Without the engine flush a synthetic motor oil will use its inherit high detergency properties to clean a dirty engine resulting in a high volume of dirty oil being trapped in the oil filter. Furthermore, dirty oil has a tendency to burn more than clean oil resulting in an increase in oil consumption. If the newly installed synthetic motor oil becomes very dark (except for diesels) after only a few hundred miles, chances are the engine was still dirty upon changing to a synthetic motor oil and an engine flush and/or another oil change is warranted.

Vehicles with mechanical problems are not good candidates for switching to synthetic lubricants. Synthetic lubricants will not reverse any mechanical problems or defects.




Do synthetic lubricants cause seal leaks?
NO. Defective seals cause seal leaks, not synthetic lubricants. Unfortunately, this myth is still being perpetuated today by people who know little to nothing about synthetic lubricants. Why is that when a seal leak develops when using dinosaur (petroleum) oil it's the seal's fault, but when a leak develops using synthetic lubricants the synthetic lubricant is the suspect? Synthetic lubricants are required to possess the same seal compatibility characteristics as today's dinosaur oils. Often car owners do not realize that they have a seal problem when using dinosaur oil. Dinosaur oil will often volatize or coke around a seal defect, leaving little to no evidence of a seal leak. Synthetic lubricants however possess a very high thermal stability and resist evaporation. These exceptional performance characteristics, coupled with synthetic lubricant's inherit "creeping" ability, will unmask a seal leak not readily visible before.


Should I use oil additives with synthetic lubricants?
ABSOLUTELY NOT. Everything you need for lubrication and protection is already in the synthetic oil. Synthetic lubricants are chemically engineered and additional additives can upset the oil's precise chemistry, or worse, interact with the oil in unpredictable and harmful ways. Save your money and your equipment - skip the additives.

 

appreciate the feedback.

 

I changed to Mobil 1 in another car that had 35K on the engine,and the oil pressure dropped significantly,ie. the dash warning light was on under 1500rpm hot.I've heard this from others as well.
There's a newer blend of Mobil 1 that helped with that problem however;it's the 0W-40.
The Lexus will keep getting clean dinasaur oil @ 2K intervals,after all,these engines go many,many miles this way,under far worse conditions.The factory has done it's own testing,and they don't specify it one way or the other.

 

The dealer has me change the oil every 5000 miles, and claims it's unnecessary to do anything else. They flush the system every time it's changed, too. My car has 69k on it, should I be changing it myself every 2 or 3k or whatever? or is it needless worry?

 

i was thinking...i've used synethtic for the last two oil changes. but i think there is still a lot of residue from the "dinosaur" oil that was being used. should i change the oil, and change it again at 500 miles or so ??



how else do you flush it?? i mean putting in a bottle and letting it drain out doesn't seem to be the best thing to do...

Arthur

 

Change oil and filter at 3-5k is more than enough, if you drive it REALLY hard and live in a hot place with lots of dirt picking up then maybe 2k might be worth the extra $. But it's all depending on the thinkness of your wallet.

SCv8,
What car overheated after you switched? I hope it's not your Lexus. :eek:
I had my 96 ES for 50,000k miles now, and change the oil with Mobil 1 Tri-syn my way and no problems what so ever. Mobil 1 Tri-syn is probably the best stuff out there, whatever that caused the overheating it's not the oil.