Swithcing to synthetic oil at 42,000 miles good or bad?

[cneculae]

hey guys
I just recently purchased a 08 corolla with roughly 42 miles on it i assume that the previous owner uesd convential oil 5w-30. I was wondering if it would be wise to do the transition from conevntional to synthetic? I want to use Mobil 1.

Thanks

Cristian

[PhatRoyale]

As long as you aren't burning oil right now, it's never too late to switch.

[tarbasd]

Maybe a waste of money, but it won't hurt.

[cneculae]

Ok guys that cool the reason I ask is beacue i have a 4E-FTE motor from a starlet in which i switched from conventional to synthetic at around 76,000 miles and the seals started to leak really bad. I was curious if the same could happen to the corolla?
What do you think?

cristian

[PhatRoyale]

Whatever happens will depend on how well the car has been maintained, are you the first owner?

Are you religious with oil changes?

But considering that the car is only a year old, you should be okay.

[shadowtag88]

imo.. better now than later... if you really want to.

cuz lets say you do it later.. and theres schtuff in the engine after all that driving. maybe around like 85-90k miles.. and you switch to synthetic.. the detergents and stuff may wash away the sludge and crap and MAY (a big MAY) cause your car to start leaking oil. because certain seals have worn away over time...

but lets say youve been keeping the engine clean the whole time.. then that might not happen..


eitherway.. nothing bad can come of it... just more expensive from now on..

[JasonA]

Yeah, at this low mileage, I don't see the harm in it. I don't really see the point either, but you won't do any harm. Are you looking to extend your service drain intevals? If not, and you change at 5,000 miles, there's no reason to use anything other than conventional GF-4 API SM oil.

[Raddman]

tarbasd;2664996]Maybe a waste of money

Maybe not,

Mobil1---$24 every 8-10,000K,

Conventional oil---$13+fliters every 3K

[JasonA]

Mobil 1: $24 + $5 filter every 10,000 miles = $.0029/mile

Conventional: $12 + $5 filter every 5,000 miles = $.0034/mile

But if your car is under warranty, you're changing oil every 5,000 miles anyway. Plus, Mobil 1 recommends to not exceed the manufacturer's recommended oil change interval, which is every 5,000 miles. Plus, research on UOAs on BITOG demonstrate that even with synthetic oil, 6-7k miles is about all you want to run on these engines. So if you stay conservative and change your Mobil 1 every 7,500 miles, your cost/mile is more than conventional, at $.0039/mile.

[Raddman]

change your Mobil 1 every 7,500 miles, your cost/mile is more than conventional, at $.0039/mile.

Been changing Mobil1 every 10K with no problems, in fact I just did it today and the oil looked like it could go another 10K! 103K and my engine runs smooth as silk!

I'm just saying it works for me!

[NMGeorge]

Originally Posted by Raddman

Been changing Mobil1 every 10K with no problems, in fact I just did it today and the oil looked like it could go another 10K! 103K and my engine runs smooth as silk!

I'm just saying it works for me!

^ and THAT, my friends is the point. If you decide to go synth, run out your miles between changes. I have read of so many folks that go synth and STILL change every 3,000 miles. Come on, look at your application!

[Sean 06 Corolla S]

I would always change to synthetic mobil 1. I changed mine at 42k. I would change it if it had 250k

[PitBoss1]

I bought my '06Corolla used with about 24k miles on it. The previous owner had never done ANY maintenance on it, including an oil change! I got a tremendous discount on the vehicle due to this fact. When I got it, the first thing that I did was do a change using Mobil 1. I then changed it again with Mobil 1, 3k miles later. The car now has 65k miles, and runs great. I am changing every 10k miles, using Mobil 1. So far, no trouble at all. I am hopeful that the 10k interval is not too long. If the consensus here is that that interval is too long, I will drop down to 7.5k miles.

[JasonA]

Here are a few UOAs with synthetic oils in our cars:

Valvoline SynPower @ ~6,200 miles
http://www.bobistheoilguy.com/forums...300954&fpart=1

Amsoil ASL @ ~10,000 miles
http://www.bobistheoilguy.com/forums...221109&fpart=1

Pennzoil YB @ ~5,000 miles
http://www.bobistheoilguy.com/forums...221029&fpart=1

You can see that even with the Amsoil, many didn't recommend an OCI of 10,000 miles. The TBN wasn't all that impressive. And it's starts out higher than the TBN on standard Mobil 1 as well.

Bottom line: if I'm going to run Mobil 1 (or any oil) out past Toyota's recommended oil change interval, I'm getting a Used Oil Analysis to make sure that I'm doing the right thing. There's enough evidence that doubling the drain interval is not necessarily the best thing to do. So rather than stew over it, I buy a name brand conventional 5W-30 on clearance and match it with a Toyota YZZF2 filter. I have an oil change for less than 15 bucks. Besides, I like getting under there periodically to check for leaks, condition of CV boots, etc. If you're like me and don't put but 10-15,000 miles a year on the car, getting under there twice or three times takes all of an hour (total, for the YEAR), and brings you some added piece of mind. Now...if you put 3,000 miles a month on it, and are truly driving 100% highway miles, then maybe I'd think about a different oil and extending the drain intervals. But I'd still be cautious with 10,000 mile intervals, as documented in those UOAs.

Every situation will be different.

[Raddman]

Recommended usage --> usually always works in favor of the supplier!