Better mileage @ higher RPMS????

[sixstringthing]

Ive been using pretty much all 4th on the highway recently, usually around 3k rpms (as opposed to like 1700 in 5th) and to my surprise, i actually seem to be getting better MPG, its pretty noticeable on the needle. I used to spend like $16 a week on gas now im spending around $10.... what gives?? Not that im complaining or anything

 

[merc123]

There has to be something different in driving style.

 

[tripsober]

overdrive when it is on your car drives at lower rpms to save gas..... so i am guessing lower rpms you use less gas 8^)

 

[nickthegenius]

Ive been using pretty much all 4th on the highway recently, usually around 3k rpms (as opposed to like 1700 in 5th) and to my surprise, i actually seem to be getting better MPG, its pretty noticeable on the needle. I used to spend like $16 a week on gas now im spending around $10.... what gives?? Not that im complaining or anything

If there is a 1300rpm spread between 4th and 5th, you should probably go have your car checked out. My Sentra started doing this before the clutch went out. The spread between 3rd and 4th kept getting bigger and the clutch would hold better in 3rd. Then, when I'd go into 4th it would rev higher than normal due to the slippage. Maybe your clutch is shot.

 

[sixstringthing]

Oh the rpm at 5th was just estimated, might be higher.

I have been driving differently, ive actually been getting on it more and shifting a bit higher. Makes no sense but I don't mind this at all.
The only thing I could think of is I was lugging the engine too much before, but i somehow doubt it.

 

[Indiana]

Lower rpm does not always equal better mileage. Engines have a range of peak efficiency. You can hurt your economy by going to slow.

If I remember right, the best mpg is had when your rpm is just below peak torque.

 

[40th GT]

I think it depends on the throttle control (steadyness) and how much the throttle is open.

 

[CanadaStang]

I do almost all of my driving on the highway. I get the best mileage between 50-60 mph.[stupid 55mph speed limits ] Any faster than that, my mileage goes down. Cruising 70mph isn't too much lower, but 80mph, my mileage starts going down hill. Have you ever actually figured out your mpg or are you just wondering if would be better? Also, driving in 4th on the highway will increase wear on your engine.

 

[todd4566]

Wish I could say higher RPMs was giving me better gas mileage. Since the swap to 4.10s, 80mph on the highway sux . The other aspects are great though!

 

[merc123]

So where do you draw the RPM line for driving? Is 1,000 too low and too much lugging of the motor?

 

[joshheat25]

I have an auto and it doesen't do to bad on the high way 22-25 mpg depending! At 70 rpms at about 2,250!

 

[sixstringthing]

No ive never checked my MPG, I could care less what im getting, its just a number... im more concerned with what comes out of my wallet to pay for that gas. Just by looking at the needle it's so obvious that I am now having more gas left over every week, plus gas has only gone down about two cents and I'm saving about $5 a week.

 

[CanadaStang]

No ive never checked my MPG, I could care less what im getting, its just a number... im more concerned with what comes out of my wallet to pay for that gas. Just by looking at the needle it's so obvious that I am now having more gas left over every week, plus gas has only gone down about two cents and I'm saving about $5 a week.

Not sure what year Stang you have but you said you are turning 1700rpm in 5th, which means you have 3.27 gears. This also means that in 4th gear you would be turning 2568rpms at 60mph in 4th. Looking at this a different way, to equal this given rpm, in 5th, you would have to install 4.81 rear gears [lets just say, for this example, that was such a gear ratio] It would seem to me, that a Stang with 3.27 rear gears would get considerably better fuel mileage than the same car with a rear gear ratio of 4.81
Next time you go for a drive, say 100 miles, try filling your gas tank right to the fuel neck with gas, drive the 100 miles to your destination in 4th gear and refill with gas. Figure out your mileage, then do the same thing back home, only try driving in 5th gear.I think you'll see which gear will produce the best fuel mileage.

 

[JonJon]

No ive never checked my MPG, I could care less what im getting, its just a number... im more concerned with what comes out of my wallet to pay for that gas. Just by looking at the needle it's so obvious that I am now having more gas left over every week, plus gas has only gone down about two cents and I'm saving about $5 a week.

you should care, mileage is a good thing to keep track of
if you have a sudden drop something could be wrong with the car

 

[CanadaStang]

you should care, mileage is a good thing to keep track of
if you have a sudden drop something could be wrong with the car

Yup, that's what I was thinking