switch to synthetic

[speedr1023]

I plan to make the switch tomorrow to synthetic oil from conventional. Is there anything extra that needs to be done? Do I need to do a flush with the syn first, or can I just do a normal oil change. I am just not sure if there will be problems if the 2 oils mix, because obviously not every drop comes out when you do a change. Also, am I correct that once you go Synthetic, you can't go back to conventional? Any quick help would be appreciated so that I can go buy everything tonight.

 

[jey_]

Just do a regular oil change and put in synthetic. Mixing the two is fine - they even sell "synthetic blends" that some people use.

I've been told that doing a lot of switching between oils is not good for gaskets (like, say, ever oil change), but no you are by no means stuck using synthetic forever if you switch.

 

[ugachs24]

I switched both of mine over to Mobil1 a couple weeks ago. The '08 has 25k on it and the '04 had 35k on it and both are doing fine. All you need to do is drain just like a regular oil change and fill it with synthetic and you're good to go.

You can definitely switch back and forth, they just don't recommend doing it often.

 

[mary900]

I switched to synthetic around 10k mi -- just did the normal oil change. No problems.

 

[speedr1023]

I did the switch yesterday. No problems that I'm aware of yet. I was going to use Royal Purple, but when I got to NAPA it was $9.00/qt, and I thought that was a bit to expensive. Maybe next time I'll try and see if there is a difference, but instead I used castrol syntec. I know in the owners manual it says you have to use GM certified oil, which RP is not, but the Syntec is. I'm sure it doesn't matter too much, but just wanted to be safe. I'm hoping to see a little difference in MPG, but not expecting a lot. I will be driving about 4hrs next weekend to Cape Cod, so I'll know with all that driving.

 

[wilb3]

Switched to Mobil 1 after about 1yr of owning the vehicle and about 40k miles- no problems. Maybe even a .5 mpg increase!

 

[2001Yuke]

I just called to schedule my oil change, the owner of the shop has a Yukon and told me NOT to switch. He said that he will tell me more about it when I get there but it "opens up a whole new can of worms". He has had head gaskets go bad, and LOTS of seals leak after the switch. NO BUENO.

 

[Mo Seawell]

I just called to schedule my oil change, the owner of the shop has a Yukon and told me NOT to switch. He said that he will tell me more about it when I get there but it "opens up a whole new can of worms". He has had head gaskets go bad, and LOTS of seals leak after the switch. NO BUENO.

So what did he say?

 

[Jeremy_K]

I just called to schedule my oil change, the owner of the shop has a Yukon and told me NOT to switch. He said that he will tell me more about it when I get there but it "opens up a whole new can of worms". He has had head gaskets go bad, and LOTS of seals leak after the switch. NO BUENO.

I don't believe that for a second. If anything, an engine running synthetic runs cooler. Less friction, less heat, simple science. As for the seals leaking, that has been an ongoing debate since synthetics came on the market. My view on it is that if you already have an existing leak, the synthetic oil will magnify it. I switched to full synthetic everything on my car which had a few leaks and they seemed to leak more with synthetic. It's more slippery than regular oil and coats the metal better than regular oil. I would think the benefits would out weigh the risks. Detonation and abuse blow head gaskets, not oil.

 

[withac]

I emailed an RP rep with questions about using Sea Foam with RP. His response addresses the questions and concerns about synth. causing leaks.

He said;


Royal Purple has natural solvents that will act like the sea foam. It cleans over time and will not shock the system with debris, like the sea foam will. I do not think you need the sea foam nor do I recommend using it with our oil. If you are concerned about what is in your engine and want to clean it out, but do not want to harm the motor, change your oil filter more often. The filter change will help keep the dirt and other debris from being circulated through the motor.

As for the deposits that could be preventing leaks, this is why synthetic oils were said to cause leaks. If you had hardened seals/gaskets or they had deteriorated, then this can be true. Conventional oil will leave behind compound build up or deposits, like plaque in your heart. Over time, this can act as a clot for these seals and prevent the oil from leaking out. Now clots are not good for your blood and starving off a bearing from getting the oil it needs can also be bad. Synthetic would go in and over time, it would remove these ‘clots’ or build up, and the engine would leak. Now seals are made of better materials and vehicles are using cleaner oil and better fuel then years ago, so this does not play as big of role any more. In addition, for the year and miles you have, you should not have any trouble.

Now let us say it was 10 years older, the oil maybe was changed every 6,000 miles, and you had some overheating problems….then maybe it would be a problem. Then again you would have more problem than just your seals.

I personally have changed my parents ’96 Suburban over when it had 236,000 miles on it and they never had a problem. They traded it in after 2 years of running Royal Purple and they put on another 50,000 miles. They always ran a 5w30, never leaked or consumed oil.

 

[KennyB22]

When I bought my tahoe new in '02, my first oil change I went to Mobil1 synthetic, never had any problems and I now have 140k miles on it. I also changed the transmission fluid to synthectic right away, and never had problems, despite some people saying I shouldn't have.

 

[biomektattoo]

When I swithced to royal purple. My mechanic told me to change it after the first 1000 miles. Then after that you should be fine. He mustve know what he was talking about cuz the oil change light came on at 989 miles. Changed it now at about 4000 miles with more power and better fuel econ.
Nathan

 

[withac]

When I swithced to royal purple. My mechanic told me to change it after the first 1000 miles. Then after that you should be fine. He mustve know what he was talking about cuz the oil change light came on at 989 miles. Changed it now at about 4000 miles with more power and better fuel econ.
Nathan

To my understanding, the change oil light looks at RPMs, run time and other things, it wouldn't know if you had synthetic, in fact synthetic users often have to reset the light because it come on before the change is due.

4000 miles with RP? With normal driving you should be able to get at least 3X that many miles between changes.

 

[biomektattoo]

I am at 4000 miles and I havent changed it yet. still is in great shape. My mechanic told me that the first time you change to synthetic it actually cleans out all the old stuff. He said to change it the first time at 1000 to make sure you get all the old build up out of it.
Nathan

 

[withac]

I am at 4000 miles and I havent changed it yet. still is in great shape. My mechanic told me that the first time you change to synthetic it actually cleans out all the old stuff. He said to change it the first time at 1000 to make sure you get all the old build up out of it.
Nathan

I misunderstood, I thought you changed it at 4K. When I made the switch to the RP I was told to make the first change as scheduled at 3K then after that I could go the longer periods. As far as the RP cleaning stuff up that's what the RP rep told me, I copied in a post up the page.

 

[ria4him]

oil issues

my 08 tahoe just turned 1K miles. RP site recommends first change at 2K. RP is not GM6094M rated (which GM says you must use for warranty purposes), but is an SL rated oil (better protection but not as catalyst friendly). RP says that they will offer me their corportate warranty if GM would refuse to honor theirs for any oil related failures. Interesting...............................
Anyone ever heard of this?