I have 26,000 miles on my '06 Mazda 3 2.3l hatch. I've been considering switching to Mobil 1 full synthetic and I'm wondering if it's 'too late' in the engine's life to do that.

I've heard that synthetic will clean out the engine, stirring up sludge that may be clinging to seals, and that this may cause an oil leak.

Is this true? Not trying to stir up the conventional vs. synthetic debate, but just want to address switching to synthetic at 26,000 miles.

And, yes, i have already searched the forum for this question, to no avail.

Thanks

 

I did my syntetic oil change at 10,000 without troubles, I used Castol Syntec, the leaking you mention wont happend, unless there is some damage on the sealing, but you do need to check for compatibility, pull a cup of your engine oil, and mix it with the new one... if you see something weird happen like, turning into Tar or a layer of stuff forming on the surface... then is a no-no for you, some times the old oil is not compatible with the new one, and when they mix, there is no lubrication at all, and then you hear strange sound from your engine, like piston rods breaking or the cramshaft punching a hole in your engine block
Uncool stuff

 

backtoback

I just remember, you'll be safer if you replace your old petrol based oil with the same brand of synthetic, but still test for compatibility

 

Thanks - since I don't do my own oil changes, I'll just tell the dealer to do it (which they won't, but at least it's covered under warranty and THEY are putting in the Mobile 1

 

I changed mine over @ much higher mileage 70,000ish? (MSP though)

 

it's fine...synthetic is compatible with dino oil...who ever told you different is full of crap...just keep the correct viscosity in it...I changed to full synthetic in my protege and then changed back to dino oil, it was fine....

I only use synthetic blend in my mustang, but that is because the recommended viscosity is 5W-20, and blend is the only way they make it

 

Normally I am full of it, but in this one I have first hand experience, the bad kind... well actually second hand, some time ago, a friend of mine, had an oil refill just before taking trip, he cheeked the oil level (quaker) and it was a little low so the guy station guy recommended the synthetic pennzoil, he puts quart or something and go, like 1000 km later, the car comes to a full stop when they open the engine, has 1 piston bent and a gooey black stuff around it, bad piston bad.... yes... it was a ford, and an old one, but still, check you oils, it will only take a minute or so.

There are Semi-Synthetic or blends oils that have both oils on the same bottle so they are definitively compatible, so my theory its that the difference in brands was what killed the engine

 

nope, still full of crap....

http://www.whatprice.co.uk/car/synthetic-oil.html

http://www.motor-oil-engineers.com/F...lubricants.htm

 

what exactly is that ?

sorry for the thread jack.. that caught me as funny...

I agree w/ macdaddyslomo - i had ZERO problems when i switched to synth oil

 

If anything I wouldnt mix brands, but I still dont see an engine failure as a result, as long as you are using the correct viscosity oil

 

yeah... I forgot some words there... thats "the guy form the gas station."

and....

Came on!! I just tell it like it was... now go and put some sugar in your gas thank I also heard its great octane booster