Rather than starting a new thread, I decided to find this old one and update so all the info is in one thread.
The "winter" gas is pretty much gone from the fuel tanks in these parts. I also learned its not just a Summer/Winter blend. The fuel is modified to match the degree days throughout the year. So late winter/early spring gas is different than mid winter gas, and different than summer gas.
Anyway, to the point of the post.....
To recap, the mods to the car are: 3.73 gears w/Truetrac posi, PCM tune (PCMflorless.com), Magnaflow V6 exhaust, 180 Thermostat, and low restriction intake.
My last 4 tanks have averaged 26 mpg. That includes some traffic backups due to accidents in the commute that I thought would ruin the numbers, but didn't happen.
So keep in mind that changing gears like I did (3.08 to 3.73) is not going to blow your fuel economy out the window (like so many posts said). When you drive with a light foot, and keep your speeds under 67 (I cruise at 65 mph @ ~ 2300 rpm when possible) the fuel economy should not be impacted, depending on mods done.
I have to admit, that the week I was off from work, and working on the car, I was hammering the throttle often, doing 0-60 tests, peel outs, etc and also just doing around town driving, and short trips such as taking the kids to school. The fuel economy for that week dropped to 20 mpg. Apparently WOT sucks the fuel.
So, what did you learn?
- The claims that changing gears will drop fuel economy 3-5 mpg in our V6 are proven bogus. Especially if other mods off set the change, like PCM Tune and Exhaust.
- The 2-3 mpg improvement claimed by Magnafow is probably closer to 1-2 mpg, and along with the PCM tune, offset any loss of MPG due to the gears. Claims that the exhaust will only give a "tenth" of a mile per gallon are most likely bogus.
- Yep, winter fuel does give lower MPG than summer fuel.
- WOT sucks fuel. So if you are wondering why your car does not get good economy, its probably due to your right foot, and not the cars mods.