the truth about rear gear ratios....
#21
RE: the truth about rear gear ratios....
ORIGINAL: MikeHawke
I believe gear ratios are actually determined by taking the number of teeth on the ring gear and dividing that by the number of teeth on the pinion. tire sizes can change and are not really relevant although you can guess your gear ratio by comparing the revolutions of the drive shaft to the tire.
ORIGINAL: Twister
Let's face it, there is a lot of mis-informationabout what a rear gear is and the ratios...A rear gear converts the revolutions of the driveshaft into revolutions of the rear wheel/tire. In other words, a 4.10:1 rear gear turns 4.1 turns of the driveshaft into one turn of the rear tire. The larger the first number is, the lower the gear ratio is, and vice versa.
Let's face it, there is a lot of mis-informationabout what a rear gear is and the ratios...A rear gear converts the revolutions of the driveshaft into revolutions of the rear wheel/tire. In other words, a 4.10:1 rear gear turns 4.1 turns of the driveshaft into one turn of the rear tire. The larger the first number is, the lower the gear ratio is, and vice versa.
#22
RE: the truth about rear gear ratios....
ORIGINAL: Tim37
ok so now your doing 60 instead of 65 so you spend a longer time at 2000 rpm thats gonna burn up more fuel.
ORIGINAL: Magiarn71
Um, read it again, I said same rpm. 2000 is not the same as 2500...
Um, read it again, I said same rpm. 2000 is not the same as 2500...
Look, its POSSIBLE to be going the same speed, same rpm - with a different rear ratio and using a different tranny gear. Same speed. Same rpm. So if you are going the same speed, same rpm - you should be using the same amount of fuel.
Thats what I said, explained again and um, just said again.
#23
RE: the truth about rear gear ratios....
bottom line is, the more gear, the more gas you will waste on the HIGHWAY doing higher speeds. just sticking with a gear swap, the higher the speed, the more gas wasted, PERIOD. Yes, I know, oh, some peoples only goes down like 2 mpg, some people cant do math at all, some people dont care. In the end, going from 273's or 327's will take more gas on the highway and in town, may not. My guess is the point of the gear swap is to get better take off, hence you WILL be burning more fuel simply because your foot is always to the floor. But, yes, if you drive Grandma style and keep it around 25 mph or so, you might save on gas... but come on, is the point really to save gas? In the end, there isnt much difference between 373's or 410's.. there isnt much difference between 355's or 373's... there isnt much difference between 327's and 355's... but there is a HUGE difference between 273's to 373's or 410's. So, in the long run, go with the most gear you can, but be willing to spend more at the pump. The smaller the gear, the more gas saved (on the highway). Thats why Ford sticks us with 273's and other smaller ones.. GAS MILEAGE. And yes, of course, there will be "special" people out there that will say different, but of course, they are "special". Hope this helps the truely confused.
Let the critics start.....
Let the critics start.....
#24
RE: the truth about rear gear ratios....
ORIGINAL: Magiarn71
No....I also said same SPEED......
Look, its POSSIBLE to be going the same speed, same rpm - with a different rear ratio and using a different tranny gear. Same speed. Same rpm. So if you are going the same speed, same rpm - you should be using the same amount of fuel.
Thats what I said, explained again and um, just said again.
ORIGINAL: Tim37
ok so now your doing 60 instead of 65 so you spend a longer time at 2000 rpm thats gonna burn up more fuel.
ORIGINAL: Magiarn71
Um, read it again, I said same rpm. 2000 is not the same as 2500...
Um, read it again, I said same rpm. 2000 is not the same as 2500...
Look, its POSSIBLE to be going the same speed, same rpm - with a different rear ratio and using a different tranny gear. Same speed. Same rpm. So if you are going the same speed, same rpm - you should be using the same amount of fuel.
Thats what I said, explained again and um, just said again.
#25
RE: the truth about rear gear ratios....
it's a commonly known fact that car manufacturers put tall gears in cars with lots of HP in order to meet emission and fuel comnsumtion requirements.
That only takes into account driving at 50 mph for a certain distance in overdrive.
Personally, I got better mileage from my 4.10s in my '03 GT because the engine did not have to work as hard to reach speed or maintain it.....as long as I could get into overdrive.
But, hell yeah, at 80 mph in 5th gear my gas mileage went way down with the 4.10s versus 80 mph in 5th gear with the 3.27s because I was running 600 RPM higher.
It doesn't take a brain surgeon to figure that out.
That only takes into account driving at 50 mph for a certain distance in overdrive.
Personally, I got better mileage from my 4.10s in my '03 GT because the engine did not have to work as hard to reach speed or maintain it.....as long as I could get into overdrive.
But, hell yeah, at 80 mph in 5th gear my gas mileage went way down with the 4.10s versus 80 mph in 5th gear with the 3.27s because I was running 600 RPM higher.
It doesn't take a brain surgeon to figure that out.
#26
RE: the truth about rear gear ratios....
good thread......
i also will use NOTHING but 4.10's
my cars have just run too well with them.
had people swear i was lying about heads , cam or whatever b4 at the track.
in my book , there is no substitute (unless your gonna twin turbo or blow the car)
i also will use NOTHING but 4.10's
my cars have just run too well with them.
had people swear i was lying about heads , cam or whatever b4 at the track.
in my book , there is no substitute (unless your gonna twin turbo or blow the car)
#27
RE: the truth about rear gear ratios....
V8 2005 Mustang GT Premium 4.6L 3V 5 speed automatic w/ OD. Pirelli (PZERO NERO) P235/55 ZR17 98 W m+s all around (W= 168 mph) 32 psi x4 per door jam ; stock throttle body: It is a twin 55 mm aperture; 87 BP/Amoco .
5 speed automatic w/ OD does anyone know the gear ratio (presumably less than 1.00) while u r going down the interstate in OD (overdrive) @ 70+ mph
...(not the final drive ratio which i assume is 3.31) but the gear ratio
http://www.seniorsix.org/e3info/speedcalc.html
what u would put in this site (above) under gear ratio
5 speed automatic w/ OD does anyone know the gear ratio (presumably less than 1.00) while u r going down the interstate in OD (overdrive) @ 70+ mph
...(not the final drive ratio which i assume is 3.31) but the gear ratio
http://www.seniorsix.org/e3info/speedcalc.html
what u would put in this site (above) under gear ratio
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