adj86

Hmmmmm...... didn't know we could run our cars off that. I kid, I kid. I know you meant cumulative. Welcome to the forums.

Potter14

I had a 2005 v6 and its 17 city and 25 highway STOCK. I put dual exhaust, cai, tune, spacer, and coil pack all on it. Thinking maybe 35 hp added at crank, BUT I was going after mpg and i was getting over 30 on highways. I drove 50/50 highway to country roads and averaging 29mpg using the full tank.

So adding mods like these, and driving good really do help mpg.

Nuke

First, this thread is almost 2 1/2 years old. Second, duals on the 4.0L yields no hp gain. CAI with a good custom tune (not a canned tune) yields 15-20 rwhp. If you put a TB spacer on, you've lost ALL credibility here (it makes a great paperweight and xmas tree ornament). And the coil packs may gain single digit rwhp IF you're FI. You're thinking wrong.

Shane780

My ford racing tune improved my gas mileage by a little bit. I now get 30mpg hwy 20ish city. Have been for 2 driving seasons now.

Tires and rims might make a difference. Making sure your alignment is correct and your wheels balanced will help in the long run.

Dino Dino Bambino

My gas mileage improved after installing these mods:

Steeda UDPs & DIY CMDPs
2010 engine heat shield & DIY undertray extensions

Here's the stock undertray and heatshield on a 2010 model for comparison.

99GTvert

Is that a tune the dealer installs to not void the car's warranty?

Shane780

tune that doesnt void warranty. Yes and No.

The ford tune comes with a warranty. Technically your engine is under ford racing warranty now.

I use to work for the dealership I bought my mustang at and they are very good about after market parts and performance parts. If the performance part breaks, its not warrantied. If a performance part causes something else to break and they can prove that, the part that was broken is not warrantied. Now if say my rear gears go, my aftermarket tune did not wreck my rear end, they are still warrantied.

Say if my pro cal tune, caused a number 8 cylinder failure. Ford racing would warranty the engine and not my ford dealership. However since my dealer installed the procal tune for me, they would be dealing with ford racing and not myself.

I personally like getting my ford performance parts installed by my ford dealer, they are always more then happy to help customers.


I also have a VMP tune. The VMP tune is superior to the ford tune, much more power up top. The ford tune however i really like, the low end torque gain.
I more so liked the fuel mileage gain compared to stock with either tune. I gained about 2-3mpg highway with the ford tune, and 1 mpg city. The vmp economy tune was about the same as the ford, but lacked the torque.