On my way home tonight. I don't get to drive on the hwy much, so I was pretty excited to see how well it really does on the long stretch.

 

i hear ya, those hwy stretches are always nice

 

I don't take mine out on the hwy much either. Today I averaged 23.1 mpg on a 100 mile trip. RPMs were mostly in the 2100-2500 range in 5th gear with the 3.73s. That's actually just a little better mpg than I got before the Kenne Bell was installed.

 

I have also got 24-25 on long highway trips.

 

The best I've mpg I've ever had on a highway trip to the coast was 28 mpg, due to having to drive between 60-65 mph all the way because of traffic and lots of law enforcement officers...

 

Dam I get 18 city and 27 highway with the s/c. Before the s/c I got 14 city

 

I was in a slow (for a highway) Mustang cruise last year up to a car show. It was a 2 1/2 hour drive early morning with no traffic. Average speed was 50 - 55 MPH. I reset the computer at the start and I got 31.99 MPG when I arrived. Victoria to Parksville for those that are familiar with the Island.

 

Aerodynamics are bad in S197's, so the best mileage comes from cruising in the 45-55 mph range. Having said that, I get about 27 mpg at a constant 65 mph, and it drops down to 24 mpg at a constant 75 mph. Around town, I only get 10-15 mpg, depending on how much I dip into (and flash) the stall converter (4,300 rpm stall speed!).

 

Got up to 27.5 MPG driving on I94 from Chicago to Minneapolis with the cruise set at 75.

 

Switzerland: GT model, 20.5 mpg on average speed of 75 mph
I haven’t been to US for more then 15 years. What changed since then concerning speed limits? Are there still various speed limits for each state? Over here we can drive 75mph. Less then 100miles away, Germany still offers unlimited motorways for the most part. Nice, isn’t it?
Ciao
Juerg

 

Most states have 65 MPH or 70 MPH limits on the interstate highways. Many of the sparsely populated western states have 75 MPH limits. The highest limit I know of is 80 MPH in a section or western TX. However, in densly populated areas around cities there may be 60, 55 or even 50 MPH limits.

Montana used to have no daytime speed limit, other than "reasonable" and prudent. Montana recently instituted a 75 MPH limit in part because too many people from other states & countries were going to Montana for the sole reason of driving very fast.

Because the US is so large and so diverse, it makes little sense to have a single national speed limit.

 

Mine says 24.9 currently. I reset it a while back. Probably about 5K miles. I have 8.8K now. Almost all highway. 55-70 mph. I usually hammer it down when I get a chance to accelerate but mostly drive smooth and easy. 3.55 rear. No mods except shorty antenna. Oh and stingers.

 

Woohoo 80mph West Texas. Gotta love Texas.

 

My best highway MPG was an astonishing 32.1 mpg. This was on the PA Turnpike heading to Jersey, with the car kept at 65 miles per, and no cruise. Was so amazed I took a picture of the readout with my camera. Once I took it past 65 mph, it dropped to a more normal 25-27 mpg.

 

god bless texas!!!!

 

My car averages 13-14 mpg with the supercharger. Plugs and fuel filter have 7K miles on them. I cleaned the MAF and am going to change the 02 sensors to see if that helps. My datalogs show I have a slow one. I am getting the car re-tuned in late April. I am hoping to pickup a few mpg when driving around normally.

 

would replacing my O2 sensor with a bosch one or whatever improve my mileage? i have 52k on my car

 

Depends if the sensor is slow reading or dead. A datalog or CEL will tell you that. Only use Motorcraft 02 sensors though.