I have 99K on my 03 Max. Mostly hwy driving. Maunal says to replace the plugs at 115K. My gas mileage has gotten really bad. 20 mpg city, 23 mpg hwy. I'll replace spark plugs first to see if that helps. Has anybody tried Bosch Platinum Plus 4 plugs?

 

I use them and they are pretty good......

 

Stay away from Bosch! The only spark plugs that the Maxima runs perfectly with are the NGK coppers/plats/iridiums. I would not reccommend buying anything else.

 

Iridium all the way

 

GO WITH NGK IRIDIUM IX! A friend had one of the four prongs (bosch platinum +4)come off in his cylinder. He is trying to get bosch to pay for the damages.

 

doesnt the iridium act as a colder plug, also shouldnt we use ngk plus in our cars? what would be a good application for nitrous?

 

Only buy factory plugs...... which would be NGK. Don't waste your money on anything else besides those.

 

Go with NGk, I brought some already, a step colder for this spring when I install the Zex Wet Kit.

 

so... then i guess im going with a set of ngk iridium's. thanks guys

 

I would stick to what nissan puts in it--they are a platinium tipped plug thats y they last so long--and there is a reason that the factory does something.

 

I guess we should all keep the same stock air filter too then.....right. Perhaps even stick with conventional motor oil and forget about the science and technology put behind AMSOIL, MOBIL 1, K&N, AIR HOG, and IRIDIUM spark plugs. COME ON NOW! If the factory could do something that would benefit the car then they would research what is the most technologically advanced products that are scientifically proven to work and put that in or on our cars so they would perhaps last even longer and satisfy more customers.

DENSO IRIDIUM and NGK IRIDIUM IX are the best you can buy, HANDS DOWN. I have the Denso Iridiums in my 01 Yukon and they work awesome. They have inproved my gas mileage consistantly in the cold (-40) and in the summer months (+90). I have no complaints and I am glad I paid the money for them. When it is time to change the plugs in the Max I will buy the same thing.

OF course you can always stick to the FACTORY PLUGS .

 

Does anybody know of sites with good prices?

 

I have put Bosch plugs in my car at 53K miles and i have no complaints at all. I think they are great and no problems at all.
Whatever you end up getting, just make sure they are Platnium tipped, thats all.

 

Does anybody have a write up on how to change them on a 5th Gen?

 

I just bought the NGK Iridium IX for $6.99 each at Pep Boys. I'm not sure if they service your specific area. But they are much cheaper than at other places out here.

 

spark plugs.com 3.5 Maxima page

I just bought my Denso Iridiums there. They work great. Car is much better.

 

GET SOMEONE TO DO IT!!!

You can change the 3 in the front and the 1 back drivers side easy. The other 2 you need to remove the plenum to get to them. I did the 4 and just got the dealer to do the other 2 on tuesday.

 

not if he has a 3.0. i was just guessing by his screen name that it was
a 2k. but the back 3 are still a bear.