2:73 Rear End Gears??????

[X-North]

i already have the differential and im able to do it myself anyway so dont worry about the cost

 

[glfredrick]

Unless you want to switch to 13" tires, you will never ever get your truck into OD until you hit close to 80. No gains that way. Check out this chart -- black is factory. Blue is "economy" gearing and green is performance gearing. Move much in either direction and you are either overspeeding your engine or lugging it -- neither is best for economy.

In short, physics are physics, and it takes X amount of engergy to move X amount of weight through X amount of wind resistance. If you lighten, slam, shave, and modify your vehicle as much as possible for highest mileage, you may gain 10 mpg, but cost yourself almost as much as the gas. Probably easiest to simply get something different to drive if money is the motivating factor.

 

[manaen]

I think you should have said green is economy Black is factory and blue is performance.

 

[X-North]

could you post the image clearer pls ???

 

[glfredrick]

Sorry, it is a bad scan and I don't have a way to clean it up. I think that you can get the gist of the situation from the chart though. What you're reading is engine RPM in drive (not OD) with certain tires and gears.

You might want to right click, save picture to your hard drive, then zoom it to see it better.

Sorry about the blue/green thing -- I couldn't see the pic when I wrote that and was going by memory.

 

[bluestream1]

You really need to take into accout the final gear ratio of the transmission for the gear chart to be helpfull.

If your 4000lb Police Interceptor worked fine with with 2:73 rear gears your truck should as well. Keep in mind that the vehicle will have limitations, (you will have to drive in a manor to keep the engine from lugging) and if you can live them your fine.

 

[Willard]

The truck won't work with the 2.73 gears. The 4000lb police interceptor likely had a bigger motor than an expedition which weighs likely close to 7000 lbs.

 

[bluestream1]

1997 -2002 Expedition weighs 4850 Lbs. His 2WD would be even less...

 

[Willard]

that's impossible, since my ex weighs 5300 lbs., says so right on the door sticker

 

[aldive]

1997 -2002 Expedition weighs 4850 Lbs. His 2WD would be even less...

Say what?

 

[bluestream1]

Weight Info found here: http://consumerguideauto.howstuffworks.com/1997-to-2002-ford-expedition-4.htm

 

[manaen]

no way is that right, my f150 screw weighed in at 6250, and the expy is only a tad bit shorter with a whole lot more metal

 

[bluestream1]

that's impossible, since my ex weighs 5300 lbs., says so right on the door sticker

No, that's the GVWR on the sticker. The curb weight of an explorer is around 4300lbs

 

[Willard]

your right, my bad. Still more than 4000 though, and just for reference, that site says an explorer weighs like 3900 lbs, so I don't think it is fully correct.

 

[bluestream1]

I guess the actual weight depends on the model. A 2 door weighs around 3600lbs. My four door XLT weighed 4376 LBS last time I went to our landfill site. They weigh vehicles going in and out after dropping off trash to get your usage fees.