Night Raven

i would say put some more air in the tires and maybe take it in for an engine check. that's way too low for a six.

i have a manual V6 w/ castrol synthetic and AFE CAI. i improved to 30mpg on the highway recently after 15k miles.

army_eod

I dunno, guys. My 06 V6 has 4500 miles on the clock. On the highway (60-70 mph) I am getting a true 28 MPG. If my driving is divided about 75% highway/25% other, I still get 26 or 27.

I am happy with that.

Fazm

My best mileage is 31.8mpg that was on a roadtrip with just a tune. My worste tank was 19mpg and that was ALL city driving with a couple trips to the track. (with intake and tune).

im usually in the 23-25mpg range with mixed driving.

Thomas S

The manual must make a big difference. Almost all of my driving is stop and go city driving though.

TorchRedV6

I've got a V6 manual and I'm getting around 24mpg (ish) with about 60/40 town and highway driving. The manual does get better gas mileage even with regular lead foot driving!!!

Fazm

Ya, im not easy ont he throttle by any means lol. But i do cruise in 5th at anything above 40mph

jcopin

i checked last night the pressure in the tires because it was bothering me since i work and go to school not much time till weekend .. and all 4 tires were at 25 give or take 1 PSI so i put them to about 31-32 and will check again .. gonna get my oil changed with mobile 1 and try that too..then il take it to the dealer

Gearhead

The best way to record your fuel economy is with a pen & paper. I exclusively burn premium fuel, as that enables me to keep the engine RPM a little lower without a pre-knock grumble. I have recorded my V6 consumption and here is what I have so far:
4,080 miles consuming 192.793 gallons = 21.2 MPG Overall
Highest single tank full mileage = 27.8 MPG
Lowest single tank full mileage = 18.3 MPG
My typical drive is about 16 miles, which includes:
Cold-start & 25-30 MPH for 4 miles
Freeway 60-65 MPH for 8 miles
20-40 MPH for 4 miles.
I keep my tires at 40 PSIG & I use Castrol Syntec 5W-50. I have no modifications which would radically affect my mileage.

jcopin

maybe im retarded but 41PSIG? i see the "PSI" there =p

what kind of tires?
i noticed the pirelli tires that come with the pony 17''s say 51PSI max on the side the dealer had them at 25 when i checked and last night i bumped them up to 31 .. should i go higher?

Bill58

Hey, so am I! I have a 2005 Mustang GT automatic and the best MPG I have had was 23!

Gearhead

Hi Jay,
PSI = Pounds per square inch
PSIG = Pounds per square inch, gauge
PSIA = Pounds per square inch, absolute
PSI is a vague reference to PSIG and/or PSIA.
PSIG is used for pressure that a gauge would read.
PSIA is a measurement of absolute pressure
If a tire has 40 PSIG, then its absolute pressure would be 1 atmosphere (14.7 PSIA) + 40 PSIG = 54.7 PSIA
My tires are 255/50WR-17 Hankook Tires mounted upon 17"x8" rims.
Les Schwab recommends 40 PSIG, and I think they ride just right with that pressure. I would say 35 PSIG would be a minimum pressure, and I've yet to see air leak INTO a tire. Yes, use 40 PSIG.
Do let me know what paper recorded mileage you get, OK? The little dash computer can tend to be off a bit.
Thanks, Brian.

jcopin

ok work with me here people .. i just finished work and 2 finals and im barely awake..so basically i should put the pirellis to 40PSI? thats safe im assuming? given the max being 51psi lol

Gearhead

Hi Jay,
Yes, 40 PSIG = 40 PSI
You won't hurt your tires unless you go over 51 PSIG or less than 35 PSIG. With the pressure on the higher side, you might wear the center of the tire a little faster relative to the outside edges, but overall tread wear will go down. With the pressure too low, you will wear the outside edges relatively faster, increase overall wear rate, and could overheat the tire cords, leading to blowout. Set your tires to 40 PSIG, and don't let them get below 35 PSIG. If you must err, err on the high side of tire pressure. I would much rather see you put in 45 PSIG than to see you at 30 PSIG.
I hope the finals weren’t over Boyles Law, were they?
V1/V2 = P2/P1
Brian.

jcopin

nope lol

so why would the dealer or factory whichever set them to 25?=p

maniak

Don't know why they put it so low, that is NOT a safe tire pressure for the mustang with these tires.

You can find the absolute minimum safe pressure for the tires by doing a little math..

The pzero -nero tires on the mustang have a max weight carrying capacity of 1356 pounds at 51 psi.. (according to the pirelli site, I can't check the tires at the moment)..

You have 4 tires on the mustang for a total weight capacity of 5424 lbs at 51psi..

The mustang has a weight distribution of 55/45 (I read it somewhere, I"m not positive on that). since the distribution is so close, I'm going to just assume 50/50 to keep the math really simple..

The curb weight of an 05 v6 is 3300 lbs (v8 is 3450 or so)..

So, you divide 3300 lbs by 4 (tires) and you end up with 825 lbs of weight on each tire...

Each tire can hold 1356lbs.. 825lbs is 61% of 1356...

That means you need at LEAST 61% of the laod carrying capacity of the tire (61% of 51psi).. Which is 31psi. That means the minimum amount of air that should be in the tire to carry the weight is 31psi, and sine we fudged (assumed 50/50 weight instead of 45/55) it would actually be slightly higher on the front tires...

So in short.. 25psi is not safe, the tire will overheat and could seperate. 35psi will be softer (nicer ride) but will wear the edges more than 40psi would..

~Mark

jcopin

ahh ok il pump it up to about 38-40 when i get dressed and stuff
yea i kinda figured if the tire says 51 i know not to put it at max and i thought 25 sounded retardedly low

hamidlmt

some of your are getting great mileage! I haven't seen over 23-24 mph yet! arrgh!

Kamicosmos

The onboard computer says I am getting 24.5 mpg. (although I will say it has only gone up! I've not seen it decrease yet.) My 06 V6 is a manual. I drive 23 miles to work one way, a mix of city and highway. I have just under 1500 miles, car is a month old, and I have my tires at 35psi. (They were at 25 from the factory as well.)

Thomas S

You can't go by the computer. If anyone else in this thread is posting numbers from the computer, those numbers are worthless. Fill up your car, zero out the trip odometer, drive until the tank is close to empty, divide the mileage on the trip odometer by the gallons used.

Hambone

I find the computer to be pretty good, actually. The gallons used, how much I pump into the tank, and miles traveled are all in good agreement.

How far off is your computer, jimp?