What gear ratio are you running ?

What rear axle gear ratio are you running ? and if you were to change it, what would you install ? And Why would you change it ?
I'm asking because I currently have a 3.23 and am thinking of going to a 2.76 (my rear tire are 28" DIA (235/70/15).

went from a /6 to a 318. then changed from a 391 to a 353, last year i went to a 323 and so far i'm happy with that.

My engine is a 273 4brl/ automatic.

same thing as a 318 4 brl. if your after lower rpm's on the highway with better gas then
run the 2:76. but it's slower at the start as well

dix wrote:same thing as a 318 4 brl.  if your after lower rpm's on the highway with better gas then
run the 2:76. but it's slower at the start as well

The days of caring about speed and power are long behind me. Now it's all about crusin an lookin cool , Why else would you own an A100 ?

try telling HOT WHEELS that.

anyone else want to join in ?, looking for some input.

360 magnum, 727, rear ratio 325 (same as 323)

Turbocharged 400BB and a four speed manual, 3,23:1 lsd. If I hadn't sold my ride, I'd propably have gone to 2,96:1.

You guy's have got to be kidding me. Is it all highway miles you're driving? My van is a driver and I do most of my driving around town. A 4 spd with 2.75:1 gears is a waste imo. If you have that extra gear(unless it's granny) I'd have at least 3.5:1. The thing to target is the highway speeds you want to cruise at. I generally want to cruise between 60 and 80 depending on the speed limit. A good cruising rpm is between 2000-2400. You don't want to bog the motor, if you gear it to low that's exactly what you'll do, esp around town if your gearing falls in the wrong spot @ 25-35.

What's the final gear ratio in your transmission? 1:1? If so I think you are in the sweet spot already. You're running 2300 @ 60. A little high, but w/ 2.76's around town you'll be a dog unless you've got alot of horsepower to spare and @ 50-60 you're ~1800, less or more. A real graama or a nice cruiser, depending on your point of view. If it's less, i.e. overdrive, I'd go lower at least 3.5

It comes down to the power you've got at hand and what you want to do with it. If you want to cruise @ 70-80 @ 2K w/o OD then tall gears are for you. But if you don't have enough HP or you aren't in good balance with the powerband for your cam/engine/trans either stoplight to stoplight, passing or both are going to suffer. Tall or short gears. Figure that out, find your optimum.

I WENT FROM A 355 TO A 294 AN LOVE IT ON THE HIWAY

355 w/225/r70/15's
slant 6
727 auto w/shift kit
cruises comfortably at 2600??? 60+mph? not sure as the speedo doesn't work...
using other verifiable sources on a round trip - 4 of them to be specific - moving my girlfriend from over on the coast near sanfran - over the mountains and up into the valley here - i got 23 miles to the gallon...

whalemstr wrote:355 w/225/r70/15's
slant 6
727 auto w/shift kit
cruises comfortably at 2600??? 60+mph? not sure as the speedo doesn't work...
using other verifiable sources on a round trip - 4 of them to be specific - moving my girlfriend from over on the coast near sanfran - over the mountains and up into the valley here - i got 23 miles to the gallon...

How did you compute your gas mileage without an odometer ? Just askin

my girlfriends trip odometer on her lincoln towne car...

i kept track of the gas i put in and knew the mileage there and back - 4 trips kind of evens things out as to how far you are driving!!!

23 MPG... your my Hero

Iam =ABSOLUTELY!= with what seth G says above!! Thats from experience too! Today's vehicles get by with very "High" ratios 2:90 3:33-1 gears only due to multipule ratios in mostly automatic trannys - yes & some 5-7 speed standard trannys- geared way down for takeoff & thru gears to move usually what is a 2500 pound car!! Overdrive @ highway speeds! =Fuel mileage . You can not get a 300-1 ratio rear to work as a late model tranny with a 1-1 final drive ratio! Take off will suffer & the in town driving mileage will be bad! Remember =that engine has to develope some HP to move that weight! Most of our vans are 3000++ up vehicles too.Plus there like driving a outdoor movie screen down the road !! Just NOT AERODYMANIC!! If you get over 15-16 mpg?? dont even think on really improving that-- these vans were never designed for mileage anyways--They are people & cargo movers!!

Theres a member from Canada with an A pickup(blue&white) 360/727 and highway gears. That said he could get 20MPG. That was on a USA gallon ..not imperial gallon.
So with him and this guy, that's the most MPG I've heard of.
Me I'm at about 15MPG.

My best mpg on highway without being overly economic was 14.

I'm running 235/60-15 all the way around with the factory 3.91 gears...it s a beast taking off but fast its not and hwy speeds would kill it I'm sure. fuel mileage is 11 mpg at best. all original 318/727 running gear no mods. i have the 2.76 gears to install and will let you know the difference when completed.

as I see were looking for a mpg =improvement here? lets be upfront & when we quote a mileage ??= was that only @ highway speeds & what speed?? also seems no one with a 2:0- /3:00-1 ratio quotes any in town mileage?? Remember - these large Boxes we drive are NOT made for mileage!!

BILL Carson wrote:I WENT FROM A 355 TO A 294 AN LOVE IT ON THE HIWAY

Bill any idea of how much your mileage changed before and after your gear change ? And how bad your low speed power was effected.

the 11mpg (the best the possum van has seen) is all "city" miles same gas pump and fairly short distance start - stop driving.allowing it to worm up,and using most of the tank between fill ups. I didn't want to say it but i find it hard to see this thing making 23 mpg considering newer trucks with fuel injection o2 sensors,overdrive trans and all will not get that mpg just saying... i will be happy if this thing gets to 15 mpg. btw the way I strongly agree with Twinpilot It was never meant to conserve fuel or make great mpg. its a work van the reason for the gear swap for me is so i can run hwy speeds. Gas price right now is a non issue at $1.68 a gal.

playnpossum wrote:the 11mpg (the best the possum van has seen) is all "city" miles same gas pump and fairly short distance start - stop driving.allowing it to worm up,and using most of the tank between fill ups. I didn't want to say it but i find it hard to see this thing making 23 mpg considering newer trucks with fuel injection o2 sensors,overdrive trans and all will not get that mpg just saying... i will be happy if this thing gets to 15 mpg. btw the way I strongly agree with Twinpilot It was never meant to conserve fuel or make great mpg. its a work van the reason for the gear swap for me is so i can run hwy speeds. Gas price right now is a non issue at $1.68 a gal.

I also do not see 23MPG as he stated. I would like to lower my cruising RPM's , and if that helps the gas mileage all the better. And someone said about newer car weighing less. Well that is a misconception, truth is most weigh more than older vehicles. Do to safety equipment AC , more lavish interiors, power windows and all of the things we demand as consumers today. My PT Cruiser weighed 3400lbs/ the new dodge Challengers are pushing 3800-4450lbs. As far as the $1.68 a gal price for fuel, we all know that ,that can change the moment that someone on an oil rig has sick tummy, or stubs their toe.
I just happen to have a set of 2.76 setting in the garage. And wondering if it is worth the time to change them out.

Seth G wrote:You guy's have got to be kidding me. Is it all highway miles you're driving? My van is a driver and I do most of my driving around town. A 4 spd with 2.75:1 gears is a waste imo. If you have that extra gear(unless it's granny) I'd have at least 3.5:1. The thing to target is the highway speeds you want to cruise at. I generally want to cruise between 60 and 80 depending on the speed limit. A good cruising rpm is between 2000-2400. You don't want to bog the motor, if you gear it to low that's exactly what you'll do, esp around town if your gearing falls in the wrong spot @ 25-35.

What's the final gear ratio in your transmission? 1:1? If so I think you are in the sweet spot already. You're running 2300 @ 60. A little high, but w/ 2.76's around town you'll be a dog unless you've got alot of horsepower to spare and @ 50-60 you're ~1800, less or more. A real graama or a nice cruiser, depending on your point of view. If it's less, i.e. overdrive, I'd go lower at least 3.5

It comes down to the power you've got at hand and what you want to do with it. If you want to cruise @ 70-80 @ 2K w/o OD then tall gears are for you. But if you don't have enough HP or you aren't in good balance with the powerband for your cam/engine/trans either stoplight to stoplight, passing or both are going to suffer. Tall or short gears. Figure that out, find your optimum.

In this area it's all rural. I have to drive 5 1/2 miles just to get to our small town, so the highway gears are beneficial here. I am looking for a higher ratio to replace my 355.

318-2, 727, 3.23 rear end. Most of the approx 1500-2000 mls/yr I do in town, short trips. Spinning one wheel (no sure grip) as long as I want - any condition. With wet asphalt it's a little tricky though

If I had to do more highway speeds, I would love to increase to approx 70mph with way lower rpm - 2.76 sounds quite interesting, as the white smoke at the traffic light is a couple years behind... (I might change with my Charger - but then that car would have 3k+ on the highway, which I do most with that one....)

Mileage I get is 11.4 mls/g (US) - no matter if idling for hours or "racing" the highway (max. 60-65mph @ 3000)

Here are the ugly details
https://www.spritmonitor.de/en/detail/924986.html

Be aware - it shows l/km as standard, instead of mpg.