gas mileage... and coil pack
 

So we did a full service on our 2000 Convertible 5-spd

still getting really bad gas mileage
did new plugs and wires - but the ignition seems fine, do coil packs just get bad on these cars? I don't really want to spend $90 if it's not going to add any benefit

it seems like a simple enough install, 4 screws and 7 plugs - right?

IIRC my screaming demon coil was like $70, what is bad gas milage to you?

13.7mpg

that's worse than my E55 AMG :icon_screwy:

What kind of driving? I see your in Cali is there a lot of stop and go?

Have you done the fuel filter and air filter

How are you measuring fuel mileage? Remember when your gauge reads empty there is still a little bit of fuel left in the tank. Fill it up completely, and before you leave the station record your mileage. On your next fill up, fill the tank completely and make a note of how many gallons it took to fill again and what your current mileage is and do the math again.

we live in Cali, but nothing like LA traffic :) he's pretty much driving to school and around town - probably 90% city driving

fuel filter was done with the full service and the air filter is brand new

yes, measuring the amount of gas vs the miles driven, here's the app I've been using for one of my other cars..

http://badges.fuelly.com/images/sig-us/109320.png

so in regards to the coil pack, that's pretty much the only thing we haven't replaced - the car has ~145k miles on it

have you guys seen improvements swapping this out?

there's no stuttering or hesitation (that I'm aware of)

I take it you put new plugs in with this service. Only thing that i'd recommend personally is dumping a bottle of Lucas injector cleaner with your next tank. For five bucks, can't really call it a risk. Especially if the car has gone through so many miles.

I can't say much for the coil pack because I never put a new one in since I got the car in the first place last year and I swapped for just a new BWD pack. I did always wanted to get the MSD one though.. It could make a difference, but not sure.

yes, my son and I installed the plugs and new wires - we put a bottle of injector cleaner in the tank prior to the plugs

I ordered the MSD coil and a bottle of Cataclean from American Muscle
http://www.americanmuscle.com/prestolite-cataclean.html

hopefully this weekend we'll get it swapped out and be able to report back!

ugh, just filled up 161.4 miles and 12.13 gallons (13.3mpg) and he drives VERY conservatively

http://www.fuelly.com/driver/ryan96/mustang

I'm starting to wonder if the 20" wheel/tire setup is not logging as many miles as needed...

245/35-R20 tires

using a tire size calculator - the 205/65-15 (oem) vs the 245/35-20

the 20" tires will make the speedo 4.9% too slow, so when the speed reads 60mph - we're actually going 63mph