Lexusfreak

Nope, I'd go for the NGK Iridiums as long as they are OE iridiums. Both will last 100,000 miles.

sha4000

iTrader: (1)

same thing i was thinking. the car rides good with the v-power in there but the only knock is that i can hear the plugs firing when i open up the hood and listen never heard it when i had the other plugs in there. has anyone ever experienced this? i took them all out and checked to make sure the gaps were all good and put them back in but i still hear it. pissed me off b/c i broke one of the bolts that hold down the ignition coil.

Lexusfreak

Get yourself a set of the NGK iridiums & find someone that can use your V-Power's. I wouldn't keep them in there too long.

additude

This doesn't make sense to me.

Based on the consensus that spark plugs do not add any appreciable horsepower/torque/performance, etc. and that lesser quality spark plugs can cause a decrease in performance, plus the fact that spark plugs will decrease in performance as they are used, I would say that the true benefit of any spark plug would be in it's longevity. In other words, just how many times can that plug fire and maintain it's like new manufactured performance.

So, I have to ask; What is the business/marketing reason for Denso to manufacture and market an Iridium spark plug for almost $12 that has a life expectancy of only 30,000 miles and also manufacture and market a platinum plug for $7 that has a life expectancy of 100,000 miles?

From a business point of view that's shooting yourself in the foot.

The only legitimate reason a person would spend $5 more on an iridium plug would be if it actually improved performance over platinum, but iridium doesn't improve performance over platinum.

So, is the market wasting it's time with iridium? Should we spend less for platinums and get more for our $$?

Wes

sha4000

iTrader: (1)

you are right, but on the same note the ik20 is $12 and my stock plug the sk20r11 which i had in after 120k and is in great condition is $9 dollars on the same site. plus the ngk iridium is only $7 dollars and offers the same thing as my stock plug. you know how you can have a regular pair of blue jeans for like $20 and then they slap a designer tag on it and then charge you $50, but ts basically the same jeans. go figure

Lexusfreak

Additude,

There are 2 kinds of Iridium plugs that Denso uses, that's what I've been trying to explain here in this thread......the IK20 is the shorter life of the 2 & only has a life span of 30k miles. I stress that folks get the OE Denso (SK20R11) or NGK OE iridiums, NOT the IK20.

PureDrifter

iTrader: (10)

since im looking to tune my car up(really bad mpg) exactly what plug do you guys recomend?

http://www.ngk.com/results_app.asp?AAIA=1187502
http://densoaftermarket.com/online_c...US&model=LS400

Lexusfreak

I'd go with the NGK IFR iridiums personally.......the NGK IX iridiums won't last as long.

PureDrifter

iTrader: (10)

thnx, pls check out my thread in the LS forum and see if u can figure out what i needa do. my mpg is insanely low.

thnx again,
-Annant

plugmaster

I double checked that 30k miles recommendation for Denso's iridiums and sure enough - interesting - they used to claim 75k miles on the iridiums (standard iridium, not platinum-iridiums).

So, Denso's current claims are:
IR Iridium - 30k miles
double platinum - 60k miles
long life (iridium-platinum) - 120k miles

But, theoretically, in terms of performance, the IR iridiums have a .4mm center electrode and the long life iridiums have a .7mm, so while the long lifes would last longer, the ir iridiums would perform better.

I can't find any plug life statements from NGK, but their iridium IX has a .6mm center electrode - thats really the only difference between the ngk iridium and the denso iridium, so ngks should last longer (although, densos should perform better)