several ?s for my 05
 

ive got a 05 mazda 3. would factory dual exhaust from a 2010 model work on mine? also does anyone know how to keep the tires from wearing uneven? has anyone used e3 spark plugs and seen any difference in mpg or power?

This my be to late but pretty sure you won't be able touse the exhaust, also if you want to spend 500 bucks to get a camber or adjustable camber to get the tires to stop from wearing. Also I just changed my plugs and used ngk and they are awesome.

did u notice any mpg gain with the plugs?

No on the 2010 exhaust. Are you lowed?

Spark Plugs:
With plugs its more a matter of type/gap than brand... These E3 & Bosch multi prong plugs are garbage, it doesn't matter how many prongs you have... the plug has a set resistance going through the electrode.

Copper will offer the best performance as they are thee most conductive element used on plugs, cheapest plug option by far, but they need to be changed a lot more often and you have to gap them yourself.

Platinum offers middle of the range performance been the second most conductive element used on plugs, mid range price and they last onger than coppers.

Iridium will offer the least performance been the least conductive, they are the most expensive option by far, and they last for a very long time. Hense why most auto-makers use them from factory... customers don't want to pay for them to get changed every 30,000km or 60,000kms.

Will you notice any performance/MPG gain in a stock or lightly modified Mazda 3? Not a chance, maybe 2-3HP on the dyno but nothing noticeable so your best bet is Iridium as they are pregapped and last for 120,000kms lol

Tire wear:

- Zero out your rear toe
- Set front toe to 0.05
- if your car is lowered get rear adjustable camber arm, if it isn't the toe adjustment should help your situation.

Exhaust:

Is not interchangeable.