Synthetic vs non-synthetic oil given car mileage

[dobrinov]

Hey guys,

I can not find a thread when we discuss what is more appropriate type of oil to use given what the car mileage is. My specific questions are:

1. Can I use synthetic (e.g. Mobil 1, 7500 or 15000) in a 2.2 5s-fe (1996) with 150,000miles on the odo?
2. Are there (or WHAT ARE?) any advantages in using synthetic versus non-synthetic besides the not so frequent oil changes? In particular does it add to securing longer life of your engine, and does it help gas mileage?
3. Are these Mobil 1, Castrol and such oils that say they are synthetic on the tube really synthetic? If they are only 10-20% synthetic, is it still harmful to the engine to use when mileage is more than 150,000m?

My concern comes from the fact the Toyota's manual that came with the car says it is not good to use synthetic when the car is brand new and when the car has lots of mileage. I still want to see what is the opinion of the experienced Toyota drivers here.

If this issue has been discussed, please point me to the thread so I do not waste everyones time here?

Thanks
nick

[bigbird]

what has the car been using, regular(dino)? teh problem with switching with high millage is that dino breaks down seals over time, when u put synthetic, because the molecules are smaller it can seep through the seals that the the larger Dino oils cant. i switched to synthetic after using dino and it did leak a little but not much. but it will most likly leak a little.

[dobrinov]

I bought the car 10k ago. Since then I have been using regular. I know of 2-3 oil leaks that I have currently. From what you say I understand that synthetic will exacerbate the problem.

thanks
nick

[bcsbadboys]

I'm happy using Havoline 5w-30 dino on my 135,000 mile 2.2L 5FSE Camry. Doesn't use any oil and there's not a drop of sludge under the valve cover.

Synthetic is great too, especially in very cold temperatures, and you might see slight gains in gas mileage. However, it has a tendency to seep out of seals or gaskets that are not already in good condition. Be prepared to switch back to dino should that happen.

[dobrinov]

Then if your seals are already in probably not that good condition, the gain in gas is not worth it the probable leaks?

[bcsbadboys]

Originally Posted by dobrinov

Then if your seals are already in probably not that good condition, the gain in gas is not worth it the probable leaks?

If you have any sort of leak to begin with and then change over to synthetic, it can sometimes make the leak worse.

You can always change back to dino if you experience any leaks. It's up to you if you want to spend $4-5 a quart for synthetic oil.

[bigdaddymak20]

I can't believe how much misinformation there is on synthetic oil. It is a wives tale about it making seals leak. But if you have a bad seal and there is varnish build up keeping a seal from leaking then because synthetic cleans better it could clean the varnish and make a leak. But by far synthetic oil protects better, gives better gas mileage, lasts longer, resists sludge far better, ect. It creates a better seal on the rings and you get less oil consumption. And no matter what anyone says, all cars even brand new ones use oil over time. My professional advice is before switching to synthetic is to use a good seal conditioner in the oil, then before changing your oil use a quality engine flush because when you put the synthetic in it will put a lot of sludge and varnish into your oil filter. And last don't believe the 3 mo 3000 mi oil change myth. That is outdated, and europe has a different oil change sytem its 9000 mi for dino and 15k for synthetic. Thats because car companies control the standards their and not the american petroleoum institute. So dont waste oil and help save the environment use synthetic oil. Its the real deal.

[dobrinov]

bigdaddymak20, thanks for the great post. Can you specify how you use the seal conditioner and give a link to an example of a seal conditioner you would use? Also would seafoam do the job for the flush?

I was also thinking if you use the seafoam in your oil it should clear varnish and boost leaks. Is this true? Then since I already use seafoam, I'll not make it worse by moving to synthetic?

[bigdaddymak20]

If you use high mileage motor oil then you dont need the conditioner. You can use any name brand oil additive its usually stop leak and it will say conditions seals. I think seafoam would work for the flush. I would just use the entire can and let it idle for 20 min before changing. But dont drive the car when using the whole can in the oil.

[dobrinov]

Originally Posted by bigdaddymak20

If you use high mileage motor oil then you dont need the conditioner. You can use any name brand oil additive its usually stop leak and it will say conditions seals. I think seafoam would work for the flush. I would just use the entire can and let it idle for 20 min before changing. But dont drive the car when using the whole can in the oil.

Perfect. I just bought High Mileage Castrol. Will run 3-4000m and then move to synthetic.

There was a previous post when someone drove his car for 100m with a full can of seafoam in his oil. I won't risk it.

Thanks again
nick

[Stillrunning]

Originally Posted by dobrinov

Perfect. I just bought High Mileage Castrol. Will run 3-4000m and then move to synthetic.

What are you trying to accomplish at 150K? Shouldn't you have thought about engine wear and oil at 30K? What will be your oil change interval (OCI)when using synthetic, thought about that? Have you considerd a cost/benefit payback? Why don't you use a little science. I would get an engine oil analysis with present dino oil ($20) to give yourself a base point of comparison. Then decide on an OCI, switch to synthetic, and do another oil analysis at the OCI you've picked. Compare your wear numbers and see if it makes much difference. You should also do a TBI on the synthetic for another $10.

I've switched to syn. on a high mileage vehicle but for a particular problem that the 0w-40 oil solved. But I go a year and 6K miles on that oil to offset the extra cost and have used oil analysis to prove out the OCI. I have not decided whether to go synthetic yet on my Camry but may try it after I do an oil analysis. I also use syn. on another vehicle I have (since new) and the oil analysis has not been that great for the cost of the cafe brand oil, so I will test another off the shelf synthetic at half the cost to see if my wear numbers get better or worse.

The real problem here is how do you equate wear numbers with a certain known engine life? Can't be done. If I were you I'd just stick with the dino at good OCIs.

[dobrinov]

Stillrunning, thanks for the valuable opinion. I bought the car at 140k, now it has 150. I have no idea what the previous owners have used. This is why I am cautious and asking all these questions.

I agree with you on the oil analysis. This is the most secure and scientific way. Last night I accidentally bumped into the following independent test between Mobil 1 and Amsoil.

http://neptune.spacebears.com/cars/s.../oil-life.html

They say the most wear with Mobil 1 come in the first 3k. Then wear drops and the oil was good for 18k, with oil top up along the way (and filter change at 12k). My real goal is to go to 1 year OCI. But I also want to see an improvement in engine performance and gas mileage. So it is a complex improvement I am looking for.

[Stillrunning]

Originally Posted by dobrinov

http://neptune.spacebears.com/cars/s.../oil-life.html
They say the most wear with Mobil 1 come in the first 3k.

I watched that test from its beginning. Those guys were pushing those oils further than I would push my oil. That test only served as a single comparison one type of oil made by Mobil1 and Amsoil in one vehicle. Mobile1 is about half the cost of Amsoil and if any value was shown it was the extra cost did not warrant the results. The test also was not for the life of the car. You won't be able to correlate their results with your engine as each engine and driving variable is different. The only way you'll know on your engine is with your own oil analysis. The cost of the analysis if done on a regular basis will probably negate any savings you may get. I do it more as a hobby and out of interest, not because it saves me money. Large, high mileage commercial trucks can do it to save money and avoid costly repairs as their scale of costs are different.

Have fun, good luck.

[bcsbadboys]

You're going to get a different opinion from everyone, because each person thinks what they are using or doing is the right way.

For you, use whatever you are comfortable with, whether it be dino or synthetic oil. Ask whether it's worth the extra cost for some of the benefits synthetic can provide.

Check out bobistheoilguy.com and you'll find out everything you want to know about oil.

[bcsbadboys]

Originally Posted by bigdaddymak20

I can't believe how much misinformation there is on synthetic oil. It is a wives tale about it making seals leak. But if you have a bad seal and there is varnish build up keeping a seal from leaking then because synthetic cleans better it could clean the varnish and make a leak.

Hopefully you are not referring to my thread. I didn't say that synthetic will make seals or gaskets leak, but if you have an existing leak it can be made worse by using synthetic because of it's cleaning abilities. In that sense, you are right, and I agree.

Originally Posted by bigdayymak20

And no matter what anyone says, all cars even brand new ones use oil over time.

I have 210,000 on my F-150. Don't add a drop between oil changes. Sits on the full mark the entire time.