OMG! someone made a bumper sticker of something I have said to a prius owner and a QT gas station.

https://themustangsource.com/f647/pr...3/#post6139978

 

have you tried putting a brick under the gas peddle???

 

I am curious.....in a automatic according to Ford they get 1 to 2 miles better...so this is because the computer is completing the shifts. So I am coined this issue about installing a LED on the dashboard that comes on when it is time to shift as the computer would be issuing that command. Has anyone ever thought of this?? Or is there third party device out there that would turn on a light when it is min to shift.

I am figuring that the computer is still generating the signal even on a manual transmission, just what input do you hook to create this.....

 

Manuals and automatics are geared differently. It has nothing to do with the actual shifting. There is no shifting taking place when calculating highway mileage.

 

Actually, the EPA Highway mileage number is a combination number using four "activity" tests:
Highway
High Speed
Air Conditioning
Cold Temperature

The "high speed," "air conditioning" and "cold temperature tests" all have stop start driving as a part of the tests - and therefore shifting.

http://www.fueleconomy.gov/feg/fe_test_schedules.shtml

 

That's not accurate.

The EPA calculates the City and Highway milage. They then run the 3 additional tests and use those results to adjust the City and Highway results. Usually it's a 10% drop on the highway and 15% in the City.

 

In a GT, the manual is rated 1 mpg higher on the highway than the automatic, it's the V6 cars that have a higher rating for the automatic.

 

I thought that is what I said?? "combination number" was intended to imply a "formulated Highway" number on the EPA specs.

 

You said it in a way that implied all 4 tests were equally balanced into the formula. They are not.

The high speed, air conditioning, and cold weather tests are combined, and then their combined results are factored into the highway mileage as a fraction.

The amount of shifting within these tests will NOT results in a change in estimated highway mileage from the car. All 3 tests combined with all factors within them included only make a 2-3mpg difference in the Mustang, shifting alone isn't going to account for 1-2mpg of that difference, it's unlikely to account for even .1mpg of the difference.

 

Drove from Tampa to Marietta, GA today in the 2013 Shelby. I filled up before I left. I got hand calculated 22.51 MPG doing average of 75 - 80 MPH. The car calculated 21.9 MPG. I was impressed for a 662 HP car to get this kinda mileage.

 

Actually, Ford 5-speed manual transmissions in the late 80's and early 90's did have that feature. A dash "shift" light would come on when it was time to shift for best fuel economy. It basically indicated low RPM shifting and I found it a bit irritating, as the computer could not foresee what gear was needed ahead, but it was an interesting feature.

=Vic=

 

Shifting aspect brings up the point as to what is considered good mileage and what is not. I would figure that the computer on board if an automatic would shift based on inputs from the system....vacuum, rpm's, and such. I bought the V6 model due to I want mileage....I have driven a 99 F-150 with 249,000 with the "romeo engine" same 4.6 V8 that was put in the mustangs in 99. Aluminum intake, so it was light unlike the normal "windsor cast blocks" , mileage was not bad for a truck, 16 to 18 consistently. That is why I brought up the shifting light idea.

 

There's no 'minimum' RPM range for shifts listed in any owner's manual that I've seen. I even just downloaded the 2014 manual and it also doesn't have min RPMs to prevent lugging. Maybe you can look it up and point us to it?

What is in the manual is recommended MPH shift points for best mileage, but I've found these hard to follow. I get around 24mpg driving back and forth to work in my GT when I stay out of the gas, shift 1-3-5-6, and keep the RPMs under 2K. My routes are on back country roads (~45-50mph in 6th gear) or thru the burbs at 25mph (in 4th/5th gear).

 

Hmm. Just noticed the 2014 manual does have an RPM range of 1500 to 7000 RPM listed as a shift point for the Shelby GT500 only. GT and V6 have no listing.

 

That's not the best shift points, the manual lists the most efficient RPM for each gear. That is, if you were to drive at a steady speed, those are the gears to be in for that specific speed. Any less and you're flooding the engine trying to maintain speed.

 

Read my lips - the manual does not list RPMs for any gears. Only MPH. Please look in the chapter 'Driving'. I looked at both the 2012 and 2014 manuals. If yours is different, please let us know what manual you are looking at so I can download it and review it.

 

I concur with skramble that there is no recommended RPM but the manual is based on MPH. I have noticed that on my other car, which is an automatic, the most efficient shift points seems to be below 2500RPM and changes to 1500RPM once it is the next gear. From my limited experience and engine ignorance, it seems that the most efficient MPG on my mustang is in trying to get to the 5th or 6th gear as quickly as possible without letting the RPM get below 1000RPM.

 

I've had my car since Apr. with the 3.31 gears, & 6sp. I have an avg of 16.6 MPG for 4240 miles. My best been 19.4 MPG and low is 14.8 MPG. I have not had a good road trip and roads hear in the UK are not that great. Constant bumps, curves and speed limit changing. I did notice when I do get on the highway hear that my car has an avg of 22-24.5 MPG showing on it so I'm sure on a road trip i can get it up there. I'm not worried about it at the moment i just love the power. LOL