There are pluses to running platinum plugs in turbocharged engines. One of the biggest benefits is that gap erosion is much lower. As mentioned, the amount of voltage required to make a spark in dense air is significantly higher than it is in lower pressure conditions. Therefore, there is a higher possibility of getting a misfire under boost with a nickel plug. Also, better ignitability is beneficial in TC engines, where the A/F can be a little more inconsistent and tumble/swirl can be more of an issue.

As far as the detonation goes, as long as the heat range is correct it should not be a problem. The hottest part of the spark plug firing end is the insulator portion; it is about degrees C hotter than the electrode. Therefore, if a hot spot exists that could cause pre-ignition (above 1000 deg. C), it will be the insulator and not the electrode. Get the heat range correct, and heat on both the electrode and insulator will dissipate to the head at a rate such that fouling will not occur, but also the risk of pre-ignition will be minimized.

Keep in mind that the following FI cars come from the factory with platinum or iridium plugs:

Saab 9-3 Turbo: NGK PFR6T-10G
VW GTI 1.8L Turbo: NGK PFR6Q
Mazda Millenia (Miller Cycle 2.3L supercharged): NGK PZFR5F
Buick 3800 "supercharged": ACDelco Part # 41-101

...and I am sure that the WRX and Lancer Evolution use precious metal plugs, too. I just don't have the part numbers handy.

 

Actually you are correct juddz..My statement was too broad...stay away from the platinum +4 plugs on FI applications...Per Bosch these seem to cause detonation problems in turbocharged engines

 

...I hear they make good fishing weights, though...

 

Nope. WRX uses Copper. All my tuning buddies recommend copper.

 

Nearly all spark plugs (whether nickel or platinum tipped) have a copper cored center electrode. The copper core improves heat dissipation. Some also have copper cored ground electrodes. So, your tuning buddies are correct. But so am I.


Back to the 30K service.... I looked through my owner's manual the other day, and could not find any reference to changing out the manual trans fluid. The only recommended trans service interval in the manual was for the automatic. Am I blind?

 

Well. seriously, copper is the better conductor, and in addition to the (small) worry about platinum plugs welding themselves in, in a FI setup, you'll want to take the plugs out periodically to check if it's running rich ofr something, so you might as well get the cheap copper ones and change them while you're looking (on a WRX, taking out the plugs is a pain in the ***-boxer motor and all) So anyway, yeah, the folks I know are all using $8 NGK coppers.

I'm sure the manual makes no mention of changing Tranny oil because they want to sell more transmissions. My bro's MR2 manual also did not mention it...but after 200K miles, we decided to change it anyways.

 

$80 an hour is fair priced in the dealer market...look around :lol: .

It's not about how you drive, it's about how you take care of the car. If you don't/won't do any maintenance on your car except oil changes in your back yard then yes we will frown upon you, or recommend a ton of stuff when you're in . Will we do the service work if applicable? Yes
Now if you barely change the oil regularly (yes we can tell) and only come into the shop for what you think is warranty work, never do the suggested repairs and/or service, then yeah next time you come in I might look a little harder at your car to see if it's covered under warranty. It's not just a Mazda thing sorry to say guys, EVERY dealership does it.

I for one can't stand all the nubs with these brand new cars that don't want to do service when it's recommended, whether at the dealership or not. Oil gets worn, even the high synthetic oils we have these days. Therefore you must replace it to prevent premature wear on your vehicle. Say you have a 50k warranty you come in only for warranty work when you visit. You come in at around 30k miles, so we recommend the 30k service. You don't do it. You come in again around 43k, we recommend the service AGAIN, you don't do it. Then around 47k or so when your tranny goes out from "racing" which we don't condone by any means lol, or some other failure that was caused by lack of service, then, unless you know someone at the shop or are just congenial and nice, we might look hard into wether you did the proper maintenance on your vehicle to prevent this failure.

That being said IF you do the services yourself. KEEP THE RECIEPTS. Then if something comes up like that situation, you can say you did it yourself and here are the reciepts to prove it.

Protege's are pretty simple cars and hard to mess up. Now if you start talking about the Mazda3's, 6's, or RX-8's, my advice to you, if you don't know what your doing or have just changed oil on your vehicles your entire life then don't do the any of the services yourself, because your going to mess something up. I've seen it too many times before. Chew on this one. This guy comes in for a repair on a Mazda MilleniaS, we tell him what's wrong with it, he won't pay that kind of money to fix it ($300 and change). A YEAR later he comes in with a bucket full of bolts and a car on rollback with the engine half torn apart. We tell him it's going to cost about $400 figure out where everything goes again, then we could re-diagnose it for $80 and fix it for him. He says ok. A guy spends the better half of 2 days putting that car back together right. The customer comes in and they tell him what's wrong with it and it would be $480+ the cost to repair it. He says he can't afford it and he wants to take it home. They say not without the $480, he gets mad, tries to sue and loses his car and any credability with our shop. Now if he would have had us fix it the first time he wouldn't have been in that situation.

As far as the Mazda Speed Protege's go, I for one know of one with around 350+whp on the stock block, stock tranny, lightnened flywheel, better clutch, bigger turbo, injectors, standalone, etc.

Just food for thought. I'm not trying to say dealers are out to cheat you, because they aren't. Are they there to make money? That's obvious, aren't we all? , it's part of the vicious cylce of life. If you want to be cheap, then you should have bought an old *** $1000 car or something. You can't be cheap on new cars. They will run forever if you take care of them or be a money pit if you don't.

 

Oh on manual trans fluid we drain and refill at the service intervals. Does it need it? Probably not, but it won't hurt by any means. Especially if you're hard on it. It's thicker oil, but it still can break down like any other oil.

 

yeah, maintenance is key. the 30K mile service from the dealer is definitely a little high in price though. i guess i luck out since i buy all my stuff through my roommate's auto shop so i have documentation in their system of buying it and he looks over all my major maintenance stuff. anyway, $80 is market rate these days, unfortunately.

 

Thanks for the help all. I did the oil/filter change, air filter, and spark plugs myself, had a lot of fun, and saved a bunch of money to boot! The oil filter is in a not so easily accessible place, but with the right tool and a little patience it's not hard at all. I was surprised at how easy it is to get to the plugs after removing those 4 10 mm bolts and then the boots. I'm still taking my car in for the multi-point inspection because I'm certain that I'll be replacing my brakes soon, and there are a couple squeaks that I need to have fixed- one is in the driver's seat belt mechanism and the other is actually the shifter.