I usually just fill up my tank. I reset the odometer and then run it till the fuel light comes on. I fill it up and divide the miles on the odometer by the gallons I put back into the tank.

I average about 17-18 mpg around the city. I never hit the highway. Maybe once a week for about 10 minutes at most.

 

Anybody know how intake/exhaust usually effects mpg on the modulars? just drove from MD to SC. Hwy mpg @ 27.1 driving w/cc on 75mph (3.55s, ofcourse). I'm pleased, to say the least. Have a JLT RAI and a LM1 cat-back, do they help our cause? Thanks.

 

I have always figured any reduction in resistance would help MPGs.

OT,Do those SLPs drone much inside the car on the HWY?

 

The SLP LM2's on my old GT droned a bit at around 1800 RPM, but I was always above that on the highway with the 4.10's.

I have Magnapacks in the Mach now and I haven't noticed any bit of drone. Straight throughs are not suppose to drone, but drone is just the nature of the beast with mufflers no matter what design they are.

 

I have to talk pretty loud to be heard inside my Mach at any speed, same for the passengers. I have Flows and they are pretty much known for that. I'm going to switch to SLP LM1s or Magnapacks as soon as possible.

 

Not sure what y'all mean by "drone". I love my LM1s b/c they're quiet at cruising but f...king scream at throttle. I have to raise my voice a little@70mph but usually it's a sweet sounding purr.

 

I avg. 22-23 combo city/county road driving. My best so far 27mpg highway at 70 mph driving to Bakersfield with c/c on most of the time. My worst hwy was 23 mpg trying to escape the Bay Area while driving in first and second gear the majority of time in commute traffic. I got 23 mpg running 80-85 to Sacramento. Totally stock at this time.

 

I wish I drove the highway more for better gas mileage, but the front end of my car wouldn't be the same because of all of the rock chips I would get. I don't actually drive my Mach to get anywhere like work or school usually. It pretty much just comes out to cruise around or run errands on nice days.

 

There are days I wish my car was just for cruising. Especially the days I have stop by Wally World. I always try to hit the stores early before the crowds get up. The county roads up here are brutal to the front end to any car.

 

Highway I got 29mpg averaging about 65mph. Haven't tested city yet, but I'd guess it would range between 17 and 22 depending on what rpm's I shift at and how hard I drive the car.