New Owner/Forum Member - Questions

[tsquare]

As a new (4 weeks) owner of a 2007 GT Premium Convertable, (Alloy Metallic), 5 spd. Manual, 3.55 limited slip rear end, I am having a ball with the car. A major move up from my previous ZX2 and ZX3.

I drive 140 miles each day round trip for work, plus visiting jobsites, so fuel mileage is a concern. What recommendations do you have for improving gas mileage on the highway? I run between 75 mph and 80 mph, and am getting 23 mpg to 24 mpg. I can live with that, but would like to improve it without losing power (to much fun pulling away from a client's Prowler <g>).

 

[1Fast05Turbo]

first of all, welcome to the site and congrats on your new Stang. There are some slight MPg improvements with a cold air kit but I don't think you'll see much change from what you are doing now.

 

[C-Liz-Go]

Congrats on your purchase and joining the site!! Your MPG is pretty admirable actually.......now if you want to spend some $$, I found adding the blower improved my highway mileage by 3-4 mpg, still doing 80 and having the A/C. And it sure makes merging onto the highway a BLAST!! Just a thought

 

[travelers]

Welcome to the site and I agree with 1fast. A CAI will help performance and maybe slight milage if you lucky. I have the C&L Racer from Brenspeed which was a big difference and I drive 100 mi round trip and I'm getting around 22-23 mpg, as long as I don't put my foot into it. You can see the other mods in my sig.

 

[travelers]

Oh yea it seem that I get better mpg at 70+ then below.

 

[stlwagon]

An underdrive crank and an electric water pump might give you a little extra mileage and recover a few ponies too.

 

[travelers]

An underdrive crank and an electric water pump might give you a little extra mileage and recover a few ponies too.

Which I just installed the electric water pump this weekend. I want to see how well it works.

 

[stlwagon]

Which I just installed the electric water pump this weekend. I want to see how well it works.

Figure out your wiring issues??

 

[travelers]

Figure out your wiring issues??

Yep its the Red/Yellow wire comming out from the fuse block that has the relay for the ecm. there are two wires the same color and the one that is 18ga is the one. Not the 22ga.

I see you have been busy moding your car.

 

[ZmanM3]

Welcome to the site.

 

[Redfire281]

Cruise control at highway speeds. Let the PCM do the math.

 

[Charlie Sheen]

http://www.turbonator.com/

 

[tsquare]

Thank you for the welcome, and the suggestions.

I notice that nearly everyone on these forums have CAI with a "tune", and the Underdrive Pulleys seem popular. So I will have to put these on the "wish list". Been a long time since I have bent any wrenches, but then, it has been a long time since I have had a car worth "wrenching" on (marriage and kids do that you know).

Question: How do the UD Pulleys affect battery charging and A/C operation?

 

[MikeVistaBlue06]

Which grade of gas are you using? With no mods it should be 87.

Since fuel economy is a goal, a good CAI with a custom tune is probably your best bet. They can tune for 87 octane and get a bit more power and mpg out of that.

I recommend a Steeda CAI. They have the best airbox, IMHO, that I have seen. The Steeda CAI airbox does a very good job of sealing away hot air from the engine. In addition, there is a place in your fenderwell that you can cut 3 holes out and install some soffit vents to get true cold air into that cavity. See attached pictures.

http://www.s197forum.com/forum/showthread.php?t=527

If you switch to premium 91 to 93 octane, they definitely can tune for that and get you more power and mpg, but then there is the cost of $0.20-25 extra per gallon.

I have the Saleen SC on mine with a custom tune and 3.73 gears. The last time I drove the car to Austin and back, I made 26+ mpg doing 70-75 on the interstate. I of course have to run 93 since my car is tuned for that.

It seems to me that once you get above 80 your mileage really takes a beating.

Try the cruise control (already mentioned earlier), and/or touch the gas pedal like it is made of eggshell and keep it between 70-75mph and your mileage should improve.

Hope this helps.

Mike

 

[freebass55]

http://www.turbonator.com/

BTW, welcome to the site.

 

[US-1]

Welcome to the site!!! I have a dead stock '07 GT with an automatic. Only thing I have done is the Predator tuner. With the 87 octane performance tune I saw a gain of 2-4 mpg. The 93 octane tune is a blast to drive but you better have 93 octane in the tank or it will rattle at upper rpm's.

Coming back to Houston from the FFW Belle Rose, Lousiana race I left the 93 tune in the car and got 25 mpg driving around 80 mph.

 

[silverjay]

actually if you didn't opt for the 3.55 limited slip you would get better mileage.
but hey 3.55 is a great gear!

a Turbo will get you 6 MPG on the highway.

 

[Charlie Sheen]

BTW, welcome to the site.

What he said, guess I shouldn't have been so rude. Have a cold one

If you do go the intake/tune route, you'll spend alot of $$ now as apposed to spending it at the pump over time. Even bone stock, your mileage is worse at the beginning as you try to "test" the car. Itemize your deductions on your Federal Tax Return accordingly...

 

[1Fast05Turbo]

actually if you didn't opt for the 3.55 limited slip you would get better mileage.
but hey 3.55 is a great gear!

a Turbo will get you 6 MPG on the highway.

Spirited driving w/FF (Fun Factor) 6MPG city/hwy....
Normal driving 18MPG city - 22 HWY

 

[s8v4o]

You may be interested in this as well. I have the SCT livewire tuner. It allows for tuning of all the octanes of course but also has an option for "normal" or "fuel economy" selection within the tune. On their site it says it can increase mileage anywhere from 1-2 more mpg. Just food for thought.