27mpg on a 2004 Auto GT

[Notchbck93]

I went down to visit the family this weekend and was very pleased with the fuel sipping capability of the little 4.6 on the highway.

Running the cruise control set at 67 mph, A/C on, no drafting of any semi's; car is all stock except for a home ported bell-mouthed throttle body, 42 psi in the tires, castrol GTX 5-30 just coming up to 3000 miles on last oil change, car just turned 40G on the clock, about a 5-7 mph head wind and even with letting my sister-in-law test drive the car for a performance run to get some ice cream, it still managed 26.66 mpg on the highway. It was also freshly clayed and coated with liquid glass.

Did I mention it is a slush box? I even dropped the hammer a few times myself.

200 miles / 7.501 to fill up on more Amoco 87 octane (26.66 to be exact). I really think if I hadn't let her go out and tromp the gas a few times it would have hit 27+ mpg on an auto. Over all I am very pleased to be back in a Mustang Gt and do not regret selling my Nissan Spec V for this car.

In real-world stop and go traffic, the car still nets 22.5-24.5 so overall I have no complaints.

I know that there are some stick guys braggin upto 30 mpg, but I hadn't seen any slushbox cars boasting 27 mpg so, I just wanted to let some of you know who care, that it is possible to do on a slushbox.

 

[40th GT]

That's very nice. You must have a freak car lol.
The best I've gotten on straight highway is like 26, and I have a 5-spd. But then again I drove a bit faster than 67mph.

 

[BurningRubber]

Thats good man, Ive pulled 25.xx out of mine mostly highway w/ some mountains... 70-80mph cruising.

 

[Stark77]

I cranked out 26.5 mpg going about 75mph the other weekend after doing full fluid and filter changes (fuel filter change made HUGE difference). Can squeeze out 22 in the city if I don't play games at the stop lights.

 

[Mustang5L5]

I've squeezed out a 27MPG once in my car. I typically average 24-25ish though since i tend to WOT merge all the time


These cars do pretty good freeway mileage. Look up the economy of the average V6 and it's virtually the same on the highway


Luckliy, i spend 80% of my time on the highway

 

[Notchbck93]

That's very nice. You must have a freak car lol.
The best I've gotten on straight highway is like 26, and I have a 5-spd. But then again I drove a bit faster than 67mph.

Running down the highway I come across some small towns that like to enforce speed traps, so I loaded up the 6 disc, set the cruise and enjoyed the ride.

 

[40th GT]

Can squeeze out 22 in the city if I don't play games at the stop lights.

That's pretty sick. What rpm do you shift at and how about your tire pressures?

 

[Greenscobie86]

This is an interesting thread.

The other day I got a mind blowing(to me) 26 MPG cruising all highway in my 98 NPI GT, with an avg. speed of 65-70MPH. I did take it too far once, 135MPH on a completely deserted, 4 lane straightaway. Plus I did a few nice rev matched 5-3 downshifts to show off for my friends, who were driving a 2002 Corolla.

Needless to say I am pleased with the mileage.

 

[Mustang5L5]

In 3 weeks i have a nice 300-mile each way drive up to Maine for a vacation.

I have my pick of a few vehicles to take, but i'm taking the Mustang because 1.) It's dangerous to drive an underpowered vehicle on an interstate and 2.) I can live with 26-27MPG at a constant cruise.


I love driving my car on the highway. With stock 3.27's, i'm cruising at under 2K RPMs at 70MPH and the car is smooth at speed. Every drive a car that just feels like it shouldn't be going that fast?? Well the Mustang feels at home at 75-80MPH

 

[Stark77]

Aluminum driveshaft will save up at least a mile per gallon - you should use that argument to persuade your wife / gf to turn this into an "approved" purchase.

 

[Mustang5L5]

How much do AL d/s's go for these days?


When i bought one for my Fox, it was something like $140.


I bought it FIVE years ago and it's still in the box

 

[Stark77]

I picked one up with my gearset so when I take it in for gear swap they can do them both. I paid $225, but I see that RPMOUTLET.com has them for $250.00. When I looked last august they were less than $200. F*** inflation/rising prices for raw material spot prices.

 

[joshheat25]

See, autos aren't that much worse on gas LMAO Thats good to hear you got such good mpg. I wish Ford mad a 5 Speed auto in the 99-04's we would have even better mpg. I tested my MPG on the way home from the beach driving strickly hwy without any stops or anything driving 65-75 with out any A/C I got 23.5 mpg and that was 73 miles to 3.1 gallons not bad for an auto with 4.10's lol

 

[BigDave06]

I get about 17 highway.

 

[Notchbck93]

I just wanted to post that it was possible with an stock auto and the fact that I didn't use any smoke and mirrors.

No K&N, No hypermiling tricks, just obeyed the speed limit well two over but 67 mph, not 55. I was even using the A/C, I'm sure I could have squeeze a little more out of it without the A/C and windows up but it was 85 out. This is why I say it is realistic driving.

I've heard that a fresh coat of wax can add up to 1 mpg and airing the tire pressure up to a still safe 42 psi can add a realisitic 1-2 mpg. It would be interesting to see if I could push it to the 30mpg mark like those uppity stick guys.

I will not go as extreme as putting a 2.73 in it, I think the 3.27 does just fine. Afterall, it is just a work commuter, if I need to get serious in a hp showdown I'll get the Notch.

If I did all highway on long commutes, I would consider the 2.73 for a simple test to see if one could get an automatic 'Stang to 30mpg on the highway. I know that my buddies 97 t-bird would always get 29-31 mpg on the highway with the 4.6l under the hood.

 

[CobraRed_96_GT]

before some mods and gears going to Tahoe and back i averaged 23.3mpg. Coming back down since it's mainly downhill i bet I was somewhere in the 26-27 range. Bolt-on NPI with PI intake aint bad, i think the NPI helps cuz of less power, lol.

 

[justinschmidt1]

I can get 20 mpg ...but ive got 3.73s and im supercharged so I guess thats not too bad.

 

[01BlkGT]

Best I get now is 19-20mpg

 

[RED2001GT]

Best I get now is 19-20mpg

Me too. I get anywhere between 16 to 17 mpg in the city and 18 to 20 mpg on the highway in my 2001 GT. I never go over 70 mph on the highway. I usually put the cruise control on and set my speed at 65 mph on the highway and I STILL get around 18 to 20 mpg with highway driving. Oh, and my GT is a 5 speed manual and it's 100% stock.

 

[40th GT]

This is an interesting thread.

The other day I got a mind blowing(to me) 26 MPG cruising all highway in my 98 NPI GT, with an avg. speed of 65-70MPH. I did take it too far once, 135MPH on a completely deserted, 4 lane straightaway. Plus I did a few nice rev matched 5-3 downshifts to show off for my friends, who were driving a 2002 Corolla.

Needless to say I am pleased with the mileage.

Did the car have any more left in it?