I have used synthetic for a number of years but it's only been the last couple of years that I've used it on all of my vehicles. When I bought the GTO it's factory fill was synthetic as was that of the Mercedes. I also buy mine for roughly $25 per 5 qt. jug but I do my own changes. The factory recommendation for our Kia w/synthetic is 7500 miles, for the GTO it's 5000, the Ranger is 5000, the Benz is 10000(!). I actually asked the tech as the Mercedes dealer and he told me that is a widely used and safe interval. Good thing...it holds 7.5 quarts!

 

There is no completely right answer to your question. It depends on engine wear. If the engine has considerable wear, synthetic will make things worse. It will get past the rings where conventional oil won't. It will leak at oil seals and gaskets where conventional oil won't. And IMO anyway, it will not provide good lubrication for the crankshaft and con rod bearings if they are worn and the clearances are greater than they should be because it is thinner than conventional oil of the same weight and does not have good load bearing ability.

I put almost 270,000 miles on a 2001 Chevy Malibu 3.1V6, using Walmart SuperTech 10w30 oil until 200,000, then switching to 10w40 to compensate for engine wear, and changing the oil and filter every 3000 miles like clockwork. It never did burn oil, and is probably still running.

It will not hurt to try it, if it starts burning or leaking oil, go back to conventional oil. Main thing is to stay away from those super thin oils with high mileage.

 

i use a synthetic blend with no problems.

but i think i would avoid any "hi mileage" oil that might swell oil seals.

I too was concerned about switching so the comments here helped me too

 

I used mine for a business route that I drove app. 250-300 miles a day. I have an '09 2.2 and changed oil every 3-4000 miles and just used 5-30 oil changes. There is no smoke, leaks or anything abnormal in the way the motor runs. Oh, and it now had 240,000 miles on it.

 

FULL synthetic oil, should be run in ALL engines, as the benefits of longer engine life, easier starting when cold,
better gas mileage , & more power, because of the reduced friction, to name a few of the most excellent benefits...

Full synthetic shoud be used in both automatic/manual trans, & diffs also...

dino juice = large molecules
synthetic = small molecules
Because of this, ALL engines since maybe 2000, have been designed,
with better seals/gaskets, to prevent the leakage of the small molecules...

At racetracks, the cleanup crews HATE it, when a track oil down , is synthetic oil, as it takes twice the time, to clean up, the small molecules from the track surface...

 

How can you say that?

The benefits (less wear, easier starting, better gas mileage and more power) are not at all likely to be noticed by the average driver, and would be absolutely minimal at best -so with the added cost of synthetic vrs conventional oil one pays a lot of $'s for any minimal benefit they might actually see.

You did miss what I would call the BIG benefit of synthetic - longer oil life which helps off-set the added cost at least in part.

However changing to synthetic on an engine that has used conventional oil may not always be the best for the engine, nor your pocket book. I switched to syn after a few years with our 2.4 and was shocked at how it ate the syn oil - when the engine had used hardly a drop between oil changes. So yeah, give it a try if you wish, but make sure you keep an eagle eye on the oil level.

I've run synthetic on some motorcycles - supposedly smoother shifting, smoother running engine were the benefits - the bikes ran the same and the shifting was the same. So I could not see any benefits/changes at all.

Some manufacturers lately specify it be used for warranty purposes - and there one has to use it in those cases. I haven't seen any articles on the why of the switch to synthetic - does anyone know of some good articles on that?

 

Valvoline.com > FAQs > Motor Oil Car FAQs > Full-Synthetic Motor Oil
http://www.royalpurpleconsumer.com/s...-to-synthetic/
http://www.pennzoil.com/learn-about-...synthetic-oil/
http://www.popularmechanics.com/cars...oducts/4213451
http://www.exxonmobil.com/MarineLube..._benefits.aspx
http://autos.jdpower.com/content/con...motor-oils.htm
http://www.hotrod.com/how-to/engine/...#__federated=1
http://blog.tischerauto.com/syntheti...-your-vehicle/
http://www.shell.com/global/products...hetic-oil.html
http://www.grainger.com/content/supp...r-oil-benefits
http://www.truckinginfo.com/article/...tic-lubes.aspx
http://www.worktruckonline.com/chann...etic-oils.aspx

 

Like I said ... So yeah, give it a try if you wish, but make sure you keep an eagle eye on the oil level.

 

Thanks for the list of articles - they made for a good read over the morning coffee.

I found the Synthetic Lubes - Article - TruckingInfo.com quite interesting, especially the comments on the 1 to 2% improvement in gas mileage.

I'm always hesitant over articles from the manufacturers, as they seem more of a sales job rather than definitive test results. But some interesting info there regardless.

Thanks again.

 

I've done it before with both my Accord and the HHR. However I wouldn't make a habit of doing so.