Just curious, I'm wondering why synthetic oil needs to be changed within what seems a short period of time - my RDX had less than 8,000 kms, I would have expected that it would last much longer?

 

8k is fine, mine during the winter periods had me change it around 5k and thats going into -km range (i.e. less then 0% remaining lol) ... honest to god I don't drive the truck like it was stolen ...must be the cold starts.

8k is what i do with amsoil (much better oil then M1) on my prelude.

 

Well, while it does lubricate better, especially at extreme low and high temps, it still gets contaminated by bi-products of the combustion process and generally "dirty".

So it is really not designed to last many times longer, just do a better job while it is in service.

 

ok, I guess I shouldn't complain since Mau's only getting 5k out of his oil!

 

I always thought synthetic did last longer.

 

It should.. but that turbo fries it up good!

 

what you guys can do is do an oil analysis on your next oil change and see if the oil still good for a few more k's.

I can't be bothered, oil change is easy to do.

 

In general, you are correct to think that synthetics do offer potentially extended oil change intervals. But for turbo-charged and supercharged cars, the bearings in the spoolers can get easily cooked by the extreme heat generated if the oil looses some of its heat stability.
Like one of the poster to this thread has indicated, synthetic oils gets contaminated by engine deposits and unburnt gasoline, and does get deteoriated over time. For normally aspirated engines, the stress on the oil is not as great as that in a turbocharged engine.

So Honda (like other car makers of turbocharged engines), has built into the engine maintenance minder system, a good margin of safety for the oil change interval, to ensure there is very little chance of the turbo seizing from the high heat.

You might be able to go to 10,000kms with the Mobil 1 in your RDX, but why chance it?

 

I'm under the impression that synthetic will last longer, protect better than dino. But I still like to change oil in my vehicles every 4000 - 6000 miles. On my street bike I change every 800 - 1000 mi. On my dirt bike I change oil after every outing. Probably overkill, but fresh oil is cheap insurance. A few $ for new oil or a lot of $$$$ for a new engine. Just my

 

Synthetic does last much longer than mineral oil. If you used regular oil in your turbo engine, you'd have to replace it every couple of thousand miles.

 

I don't think you want to use a conventional mineral oil in any modern high performance turbocharged engine. those turbo spoolers gets really really hot, and the engine oil flowing through them will get cooked in no time, and the bearings will seize.

In the old SAABs, where they used conventional oil in their turbos, the turbos burnt out fairly rapidly...

No, JMHO, I say do not even consider conventional engine oil in your RDX turbocharged engine, unless you are stuck in the desert somewhere and no walmart in sight, but some dingy oil general store which carries only conventional oil.