Averaging your three MPG figures this way is not absolutely accurate, especially if the distances driven between fillups changed a lot. You'll get a more accurate result if you add all three distances, add all three gallon quantities, then divide your total miles driven by your total gas filled.

 

Do you have the filter installed?
Muffler on yet?
Clif

 

A *lot* more accurate. For example, let's say you use one gallon to go 50 miles, then two more gallons to go another 50 miles. So 50 mpg followed by 25 mpg over equal distances should be an average of 37.5 mpg, right? Wrong. Three gallons to go 100 miles is 33.3 mpg.


For an even more obvious example, if you coast for 40 miles (infinite mpg) then use one gallon over another 40 (40 mpg), your average mileage is not infinite, it's 80.

 

Darn that confounding MATH !!

 

Yeah, but let's not get too dramatic. Malditos gave enough info to calculate his mileage correctly. He traveled 373 miles @36MPG, 400 @ 39.3, 425 @ 44.8. I can calculate how much he filled up each time by dividing miles by MPG. Then, adding it all up we get 1198 miles using 30 gallons of gas, which comes out to 39.9 MPG. He calculated 40. No big deal.

 

Yeah, the difference is minor when the number of gallons are similar for the measurements (in this case, 10.361, 10.178, and 9.486) as they are with tank measurements... it's more of an issue when people refill their tanks early at random intervals.

 

Muffler is being installed, will pick up the car in 45 min. The guy at the autoshop gave me different options. Option A replace at exhaust, Option B replace behind Cat Converter, Option C replace pipe from Cat all the way to the back. I went with Option C as he said running 2 in pipe all the way would give me the highest MPG and performance boost.

 

For y'all that have replaced their system from the cat back, have you installed mandrel bent piping or crimp bent?

Jeff

 

I "believe" there are only a few places where you can get pipe mandrel bent and I have never heard of or seen a muffler shop that does it. One of the reasons I went with 2 1/4 is because the pipe narrows with the bend.
Long story short for me, crimp.
Clif

 

Muffler has been installed, Air filter will be done on Monday (I don't have time to do it till then). Picked up the vehicle and drove it home with traffic at 5:00 from Pasadena to Rancho Cucamonga, total drive was 50.9 miles at 43.1 mpg per Trip A on Dash. Oh man could I feel the difference in acceleration, to bad I was in traffic except for the last two miles. I did the same exact trip yesterday, 50.9 miles @ 39.7 mpg. I refueled the tank when I got home and discovered something interesting. Everytime I pump I write down the miles and mpg per dashboard on the reciept. 471.11 @ 44.2mpg (per display). I refueled exactly as I normally due, it took 10.501. Do the math, that is 44.863. My display vs the math had never been off by so much. The most I had been off in the past was + or - .25 . Is this due to the mods? The noise is there but not loud to the point of making alarms go off in parking structures. The power difference is felt instantly. It doesn't sound like a golf cart anymore. I saved all the parts in case I ever want to go back and reinstall, 3 screws and remove the hooks and I can swap out the entire system. Almost forgot, I took my camera to take pictures while the car was up on the rack, but I was so excited to have the mods done that I left the camera inside the car and was the guy brought the car down, he wouldn't take it back up "just to take pix". Sorry.