Have an 04 MC no frills, trying to improve performance & gas Milage. What is the best Plugs to put in and what is the best wires to get. and approx. $$ to them. Got 69500 on the OD don't know if they have ever been done.

 

Stated plug life is 100K. Wires have no specified replacement interval and are replaced on condition

Assuming the car is running fine.... if you have the original plugs in there, it might slightly improve your mileage to put new plugs in at this point, but swapping them with "hop up" aftermarket parts is unlikely to improve mileage or performance over stock. There is no magic plug or spark plug wire the miraculously improves mileage or performance, just like there is no fuel catalysts, fuel magnets, or vortex generators. If you hop up an engine with other modifications, the benefits of aftermarket plugs and wires MIGHT start to be apparent (might not either), but on a stock engine, the stock plugs and wires are perfectly adequate.

- Mark

 

Somtimes just driving habits can get the best of us in the MINI and fuel mileage suffers. Somtimes it's just the common sense stuff like double checking your shifiting point/rpms, dropping in some good fuel injector cleaner to a full tank of gas every 10K miles, and new air filter can do the trick. And oh yeah, dont forget tire pressure. I always keep mine a few pounds over MFG Recomended on the door jam. It may not be as soft a ride, but it handles better and decreases road/tire friction IMO. Another thing overlooked is the amount of unecessary equipment which accumulates in our car...........

As far as plugs go, that depends on your driving environment/style. And most anyone here will tell ya that swapping out the Ignition coil pack and wires is a waste of money absent some huge engine mods. In my case I have a smaller pulley, and at one time used colder plugs to compensate for added heat. But I found that New England weather sort of made this a moot mod. But if I had lived in a place with hotter climates, I am sure the plugs would have worked better.

 

Of course improving performance and getting better gas mileage are on opposite ends of the motoring spectrum. Best choice is to performance drive one tank full then economy drive the next. Then you can brag one week about how the car performs and brag the next about what great mpg you are getting. Best of both worlds.

 

This is very hard to do. I always regress into performance driving when I'm trying to do an economical tank.

 

Mine has over 90k on the clock, I've since done a tune-up with upgraded parts. Big wires, platinum plugs, foam filter, hot coil pack, etc. I gained a couple hp back and a mpg or two, but nothing substantial. In fact, the biggest difference I noticed was when I bought a set of 15" Holies and put Dunlop Direzza Z1s on (a very light wheel/tire combo). And still, the mileage isn't outrageous.

The biggest thing that I've found to make a difference is driving habits and weight. After an autoX in my WRX, with the spare and everything still out of it and tires puffed up, I got 29mpg on my daily commute on back roads and in town. The car is rated for 26mpg hwy. If I'm hyper-miling a tank, I'll take it out of gear and coast to stop signs and lights. If it's a nice long coast or a long light, I'll shut the car off. Drafting/tailgating, dangerous but great for mpgs. On road trips, I'll find a semi-truck that is making good time and tuck in behind him. I'll even side-draft semis when passing them.

To date, the best my wife and I have gotten in the Mini was when the car was loaded down with us, our luggage and the pooch (75lbs), going 70-75mph on the way back from Mississippi, and we still got 38mpg. I think I could have gotten 39 if I wouldn't have filled it up with a 1/4 tank left.

 

Not necessarily - usually opening up a factory restricted intake and/or exhaust system results in better performance and gas mileage (if the driver can keep his/her foot out of the throttle!)

 

It has been dyno proven changing your plugs will net you power. But I would not solely rely on this do improve your gas mileage. You should watch how you drive. I found that if you changes gears between 2k and 2.5k and skip to every other gear (1,3,5 or 2,4,6) will help you a lot in improving your gas mileage. But considering the MINI gets between 26 and 34mpg you are doing a lot better then a lot of people on the road.

 

It's an automatic not a stick, I know thats not bad but trying to squeeze as much as possible with gas prices on the uprise again and not knowing when the last time the plugs and wires where done. it would only make sense to start with them. not looking for a miricle cure just hoping for some improvements to try to get back a little

 

Changing plugs in a stock engine will only improve your power/fuel economy if the old plugs that you took out were worn, faulty, or improperly gapped.

Unless you've got a reason to believe that the stock plugs aren't reliably igniting the air/fuel mixture, nothing you do in the way of changing plug design, using capacitor-equipped plug wires, or running a higher-voltage ignition coil will improve matters.

Igniting the air/fuel mixture is a binary operation - either it ignites or it doesn't. If your current plugs are working properly, nothing you can change in the ignition system will make the mixture ignite any "better". Think of it like using a blasting cap to ignite a stick of dynamite. If one blasting cap will reliably ignite the dynamite, switching to multiple blasting caps or bigger blasting caps isn't going to give you a bigger explosion.

 

got a lot to sleep on thanks for all the info. please feel free to suggest anymore thoughts on this but for now good night from the finally warming state of mass.

 

Don't forget about tires; not just weight.

Narrower tires with non-aggressive summer tread have the lowest rolling resistance, particularly if slightly overinflated.