Does it make a difference whether you use synthetic or conventional oil in your car? what are the advantages of each ( besides price). I am unsure weather to spring the extra 15 and get the synthetic this time after almost putting 10k on my car under conventional

 

Ibelieve it's worth it. I run 5w-30 Castrol Syntec in the engine and 75w-140 in the trans.
Cost is the only real disadvantage and if you consider that you can safely run synths twice as long (or longer) than conventional oil it makes even more sense. Just make sure your engine is fully broken in before you switch and that you change the filter and top-off after every 5(oops) "K"miles. I switched over @ 20k miles.

 

ive been using quaker 5w20 full syn ever since my first oil change, and a higher quality oil filter

 

This is a good addressing of the topic, IMO: http://en.wikipedia.org/wiki/Synthetic_oil

Another article of interest: http://www.jdpower.com/autos/article...tic-Motor-Oils I would draw your attention to the end of the article, whichaddresses the question, "Does my vehicle need synthetic oil?"

Re: the point about extended intervals with synthetic, I personally don't know what Mazda would think if you didn't change the oil in accordance with their maintenance schedule. Could it void your warranty?

 

It might very well, however, and as I've been saying all alongthe way the rules of warranty are written these days there is much room for interpretation on the companies part so they can pretty much do what they want to.I chalk this up to the warranty wars within thebusiness itself, as well as bogus lawsuits brought on by customers that either don't understand cars or are simply trying to make the quick buck from a large corporation.

I made a decisiona few years ago that I was not willing to wait five years to make this car my own. If what I have done to it voids parts of warranty, so be it.There is no reason the engine and tranny in my car shouldn't last until long after the car is OOW, and imo the synth change-over should only increase those odds. Cheap insurance, imo.

 

I will be running Semi Synthetic in mine, actually from the first oil change (free at the dealer and they use Semi synthetic Penzoil)
I normally change my oil at 3K, so I am in the 10 oil change a year club (the 3 is one month old tomorrow and is going in for the oil change). Even when I was running Mobil 1 in the F150 I was changing it at 3K. So I went back to the Semi just because I was going broke buying the Mobil 1 [8D]

 

but is there any real advantage? Besides lasting longer, does conventional oil provide any additional protection?

 

Ah, and there in liesthe tail. If you are looking for a definitive answer, you may be years away from getting it.
Some would say that all shampoos are created equal, while others swear by a particular type from a particular brand.
Some would argue thatbrand xgasoline is better while another person swears by brand y.

Get the picture?

Use synthetics if you feel more comfortable, or have had good experiences w/it as I have. Use conventional mineral based oils/lubricants if you haven't.
That's the bottom line, imo.

 

Here is another link of interest. http://www.stretcher.com/stories/02/02dec02k.cfm For you to consider, I am not here to argue, only to offer input.

 

after my valvejob on my old 89 350 chevy truck (bought truck with 25k in 92, switched to syn oil and ran it untill 2002) while the heads were off cylender walls were outstanding, crosshatching still present, no ridge at the top of the cylinder wall ect.

on the gas note ive found that my individual cars have there own preferance , same for my old man. saturn sl1 valero , f150 anything but chevron, mazda pr. wal-mart ect.

found that the cars get beter econimy over 3-4 tanks