It's been awhile since I owned a Z (Last one was a 75 280Z 2+2 and my have they changed). I came across a 2007 350Z 6sp with 12,000 miles a 65 year old guy was the previous owner and I spoke to him about it. He says it was a second car for him which he rarely drove and traded for a Maxima.

I pulled the trigger the other day and traded my 09 Harley V-Rod Nite Rod Special for it (rarely rode the bike for various reasons). The car is bone stock (or was) thus far I have only installed a Bully Dog GT tuner (Had it in my truck but decide the Z was a better spot) with a +2 timing adjustment per the posts I have read here. Next thing I'm considering is drop in K&N filters and maybe some HPS silicone post MAF hoses. Any thoughts if those two minor mods to the air intake are worth the effort?

My goal is to not do anything for mods which will drop the mpg. The Z will be my DD so I don't want to do anything to affect it's dependability but want to squeak out as much MPG as I can knowing it is a sports car.

 

leave the stock filter nad airbox if you want good driveability and no loss of low ebnd or MPG.
Intake does 3 things to a mostly stock Z; makes it sound cool, loses low end power,and brings down you mpg noticeably. They are already plastic, no need to change to a silicone hose.
advancing the timing willput some un due strain on your bearings.. ask a guy who threw a rod bearing when he juiced the timing 2 degrees up.
if you want efficiency, leav er be man, leave it stock, spend your money on wextremely light wheels and a good suspension and you will have a fantastic handling car, better mpg due to the wheels, and no problems due to mods on your engine.

 

Wow didn't think just adding K&N filters will drop my low end and MPG.

Thanks I'll look into the light weight rims.

 

+1 on not putting K&N filters on the car. The stock one's are already designed and mouthed up to pull in enough fresh air from the outside.

 

Breathing mods won't decrease your mpg.... You're increasing your engine's working efficiency by creating more availability of air for the engine... Think about it...

It will actually increase your mpg for most cars, but since 350Z's already has very good system, it will be barely noticable.

Most of the time people losing MPG after the mod is because they want to hear the mod they just put in = aggresive driving.

Lighter wheels would be your best bet for mpg.

If you have itch for mod, putting cat back exhaust will actually INCREASE you mpg (by 1 or so) since stock 350Z exhaust is a bit restrictive (back to your engine working more efficiently.) But chances are, you will end up driving more aggresively... (You know you will...) So put that into your consideration.

From personal experiance (200+ miles road trip at least 5 times a year = lots of boredom)

2005 Stock 350Z hwy mpg (23.4 mpg, calculated before/after gas fill, not the gauge)

2005 350Z with Stillen Intake (cuz it's 05'), Motordyne 5/16 Plenum Spacer, Test Pipes and Borla True Dual Exhaust hwy mpg (25.1 mpg, calculated before/after gas fill)

That's my average figure. So... I spent over $1,600 bucks (Since I bought most retail...) to get 1.7 mpg increase... yeeahhh... but it's so worth it on a convertible. (Top down + Tunnel = mangasm)

 

I have a 07 ZR and i have AEM intakes and an authentic HKS catback. If you drive it like you drive it now you should get better mileage. But i do have to agree with TheWan that its hard not to get a little aggressive from time to time to hear that roar. All that said it is my daily driver as well i would still recomend atleast an intake and catback exhaust.

 

you just bought the sports car and are already thinking about mpg..

come on man...

 

THIS

If you that concerned about MPG... YOU SHOULD HAVE BOUGHT A PRIUS!!!

 

As I said in my original post I went into this purchase with my eyes open and knowing it is a sports car which in turn means mid to low 20's mpg. I have no interest in a prius or civic or any of those other high mpg cars. I bought a sports car because I wanted one. I have no issue with 23mpg that is much better than my Avalache at 16mpg so in the end I'm saving money.

Also as noted in the original post I was not complaining about the MPG I was just asking what mods will negativley affect them. This car is fast stock but being the shade tree mechanic I am I like to tinker with my vehicles. Normally I start with exhaust, intake and programming but I don't want to spend a couple of grand to get the extra HP and only a few mpg or even worse lose mpg when in reality I will probably rarely if ever use those extra ponies.

I don't understand what is wrong to ask what mods will increase the cars performance while maybe squeezing out some extra mpg vs those which will adversly affect it. Isn't the reason for these forums so that we all can learn from all of our experiances without getting criticized? Had I posted that I bought this car and expected 30+ mpg then by all means flame me but I didn't.

That being said those of you who have posted usefull remarks worth reading thanks for the help and info.

Netko350z, Hyuk28719 and anyone else who decides to chime in with useless and unhelpfull remarks... well you get the idea.

 

a 350z is not a car you buy worrying about gas mileage, if thats the case buy a sentra

 

Nothing is wrong with your intention to save gas. I understand your logic.
Coming from 16 mpg vehicle to a 19-21 mpg car you probably want to catch something sporty and also gas saving.

There is not truly gas saving mod. If you want to save gas, then like others have mentioned just stay stock. Also MPG is subject to driver's habbit. So if you want to save gas just drive her really gentle, more likely like grandmas drive.

I just thought it's like "hey I bought a pair of chopstick. I was wondering if I can use it to poke foods, or eat soups."

Yeah, sure I guess so...

 

Thanks and in reality I realize when you put on an intake or exhaust you tend to jump on it more to hear that sweet sound so inturn you could negate the gains (From the sounds of the responses you will quickly overcome them with the Z). I just didn't want to make a big investment on a vehicle which I didn't know is allready tuned to get the best of both worlds.

My truck on the other hand is/was not tuned so precisly and the potential hp and added mpg was bottled up. By adding a CAI, Exhaust and a Bully Dog programmer I was able to gain enough HP and MPG that when I lifted the front a few inches stuffed over sized tires under her and hung a big heavy brush guard on it was still getting better mileage and quicker times than when it was stock.

 

I would suggest only doing mods if you're going to be racing. If not, a stock 350Z has plenty of kick. The 350Z is crappy for city driving, mine gets about 17 mpg. But highway driving, which I do the most, I get a respectable 25 mpg. And that's going 75 mph.

But overall it's pretty good performance for a sports car. If you do mods, just be happy with them. Nothing worse than investing money and not getting the performance you want.

 

Great post. And also good reading as i did change the intake on mine along with wheels.

 

Did you notice any benefits which would offset the cost?

 

The only thing it did was nicer sound but the wheels really added a touch to the car. As far as performance i don't think there is any benefits from it. I don't drive it hard anyways.