Wires, spark plugs and pcv valve

[nonneuron]

I bought 2008 base model (non turbo) Pt from CarMax a couple weeks ago. It has about 34,000 mile on it.

I filled it up two times so far. Last time, it had 1/4 of the tank left, and from the meter at the gas station, it said I used about 10 gallon to fill it up. However, I drove only 144 miles since the last gas station visit, so my car ended up having 14 mpg!

I was in shock, really shock. I realized even before purchasing it that Pt is not so good at mpg, but 14 mpg is, for me, unacceptable, especially this is the combination between city and high way. It's very fun to ride, but this fun was gone when going to the gas station.

Both CarMax and Chrysler say they cannot do anything about it. Well, after reading many threads here, it seems that there are some ways to improve mpg, namely changing wires, spark plugs, and PCV valve.

Since this car used to be a fleet before, and Carmax sold it a little bit after it reached 30,000. I doubt that it might not go through the major mileage service at 30,000 miles. Although Carmax certified that my car passed the inspection at many points including plug, pcv and others, I doubt that they only inspect but not replace some of these.

So I think I will buy wires, spark plugs and pcv valve myself and will have local mechanics replaced them.

As for the wire, some people recommend MSD wires. However Amazon has so many type of them, and I cannot found specific type for Pt in the manual. Which one of this is for 2.4 nonturbo Pt? Amazon.com: msd wire: Automotive

Same for the spark plugs, people recommend either Autolite iridium plugs or Bosch Double Platinum plugs, both with Gap plugs at 0.04. I cannot find the Bosch Double Platinum plugs on Amazon, but found a lot others. Can u please help me pick one? Amazon Part Finder: Slide Show Results

Again, for PCV valve, I don't know which one fit with PT: Amazon.com: pcv valve: Automotive

Thank you in advance for every Pt fans who help me : ). I just moved in town, and have zero experience with car. Pt is my first car. I felt in love with this car at first sight in 2003, and now I own it. I just love the car so much that I don't want to return/sell it back.

[nonneuron]

Oh I also found "Bosch Platinum+2 Spark Plug" at AdvanceAutoPart. I'm not sure if "+2" is identical to "double."

Advance Auto Parts: Platinum+2 Spark Plug by Bosch - Part 4314

Any opinion about this one?

[Freezinghot]

The +2 is double electrodes, so gives 2 sparks rather than one for a quicker, more thorough burn
I have the Bosch +4 and they slightly improved mpg. In theory added electrodes should work better than the single, but the single arent that bad at burning in the first place so not a whole lot to improve upon. Really the only practical way to increase mpg is plugs and wires, also you can unplug the negative battery cable , let it sit for 10 minutes, then connect it. this will reset your computer. Next time you drive it keep the rpm's as low as possible and your computer will learn what kind of driver you are and adjust settings to fit you best. In your case, lower performance to save gas. You can always go with a cold air intake,could save you a few mpg's, but the price for a reputable one isnt too practical for the purpose of saving money.
For the wires, i use accel super stock which work very good, but MSD is a very good brand, their wires should be fine. Just make sure their at least 8mm, 8.5 is perforable , but 8 will work just as well.

[nonneuron]

Thanks Freezinghot,

So I'll buy four of Bosch (4482) HGR8MQP0 2 Platinum +4 Spark Plug then:
Amazon.com: Bosch (4482) HGR8MQP0 2 Platinum +4 Spark Plug, Pack of 1: Automotive

And one set of the MSD Ignition 31159 8.5mm Super Conductor Spark Plug Wire should work, right?
Amazon.com: MSD Ignition 31159 8.5mm Super Conductor Spark Plug Wire Set: Automotive
I'm concerned because Amazon indicated "This product does not fit your 2008 Chrysler PT Cruiser"

Thanks again.

I'm still looking for PCV valve though. Any recommendation?

[Freezinghot]

Sounds like a damn good setup.
Ya, says they wont fit an 08. Honestly just about all plug wires you get are going to have equal performance, so theres really no reason to cough up a lot of money. All are going to be superior to stock. But when your getting that poor mpg im willing to bet that its a combination of things working against you. Most of which im betting is a lead foot :P
Doesnt seem to be too many different wires for the 08, but these seem pretty decent Magnecor Chrysler PT Cruiser High-Performance Ignition Wires 01-Up - AutoTruckToys.com
I would only replace the PCV valve if its cracked or damaged. The older models had an issue with the covers, but im willing to bet yours is fine.
14 mpg is going to probably be how your driving, more than anything else i think.
I would take it step at a time , and see if it improves. Its very likely that your have parts starting to wear down, but no reason to get it all at once. I recommend plugs and wires and then see if it gets better.
Also i would recommend replacing everything yourself unless you have a very trusted mechanic. Plugs and wires are pretty simple, but ive learned quickly not to trust most mechanics. Could open up a can of worms for yourself. Here a how-to so you can determine if it will be too much for you Spark Plug Guide
Always check your tire pressure as well, believe it or not that can make a big difference, not as much as the government likes to think...but it will help.

[nonneuron]

Thanks again Freezinghot,

Sound like I don't need to replace the PCV valve then. I just emailed MSD Ignition to see if it is compatible with my Pt. Otherwise I will go for the red 8.5 mm Magnecor one you suggested. And for the mechanic, I'll see if I can do it by myself first.

[Freezinghot]

Good choice, even if its kind of a pain to learn to put the stuff in, i think its worth it to learn something new. Shouldnt take you more than an hour or 2 if youve never done it before. And this forum will have info on any question you could have about it. The resources are endless

[briancpearce]

For the record, all spark plugs produce a single spark. Spark plugs with multiple electrodes are simply there to last longer. Electricity will always take the path of least resistance, i.e. the shortest gap. When one electrode begins to wear and the gap opens up, the next one will be the one producing spark. You'll see this on the E3 plugs, and multiple variations on the Bosch plugs with two and four electrodes. The only way to build a spark plug that fires multiple sparks is to have some crazy ignition coil that could deliver multiple charges to the plug down multiple wires. This of course is cost prohibitive, so some manufacturers have coils that will produce several sparks per power stroke. Any manufacturer claiming that their plug produces multiple sparks is selling snake oil. A better spark, sure. Bigger flame kernel, I'd believe it. Multiple sparks from the same ignition pulse, not electrically possible by simply adding electrodes. Personally, if you want a longer lasting plug, put in an Iridium or Platinum plug. Those are designed to last longer and not be changed as often, especially for cars like ours where you have to pull part of the intake manifold to get to them.

[quicksilverdon]

^^^^^ Agree - and I'm not sure that even if they could get multiple sparks, it'd do anything good....

[Freezinghot]

If it had multiple sparks , it would improve. Would make your engine last longer because it would clean it out. Im used to working with old engines, and the plugs usually dont go in straight or in the center, so the burns will be uneven and will leave crap all over the inside. Ignition in old cars were explosions instead of burns though, because efficiency has gone up.
I was wrong about the function of the +4 but it seems to me that there still beter than single electrode.The +4 and +2 are platinums, so will hold up to heat , your guaranteed a clean and efficient burn for the life of the plugs.