I always see you guys listing your gear ratios. Could someone give me a description of what this is. I believe my truck is 3:55. Which I assume is stock for a 98 F-150. I don't tow with my truck and am trying to get a little better "street" performance out of my truck. Would getting the gear ratio changed help? What would I like to change them to. Is this a expensive change?

I am planning on installing the Super chip and a K&N air filter system also.
What other performance boosters could I make?
Thanks
Al

98 F-150, 5speed, 4.6, flowmaster 50-series.

 

Plan on about 500.00 for a gear change, double it for a 4-whler. 3.55 to 3.73 won't make much difference. 4.10 will make it a screamer off the line, but you will lose gas milage on the highway as the engine will be turning more rpms. Unless you put on big tires and are planning on some serious towing, I would leave it alone. Spend the money on something else for the truck.

Good luck.

 

I agree with frog that you should soend the $$ on something else. Gears will certainly make a difference and if you've got 3.55's then 4.10's or 4.56's would be the way to go. However, I think there are a lot more things that should be higher in the list, like what you'[re planning on. Superchip should be first. Opening up the air intake and exhaust would be next then from there, electric fans, pulley's etc. etc! Just get ready to spend once you get started!!

 

I had what i think were the 3.31, right under the 3.55
I switched to 4.56 and did not change tire size yet, this will not be permanent. The 4.10 would be perfect for factory tires that the truck comes with. The gears put the motor in a power band that allows the motor to work easier but faster. Concern of mpg is easy to see if you can get into a vehicle that has a computer to show instant mpg read out. When accelerating the mpg might be 3-6 when crusing down road at constant speed the vehicle might get 20 in 4th gear ( put into third) and the mpg drops to 18 mpg.

with gears the 3-6 will change to 6-10
highway 20 drops to 18
Driving habits will make the difference
around town or stop and go mpg will go up becuse of efficient use of trans gears.
When going down the highway all day long the mpg will go down.
When equal city and highway the mpg stays the same but you will have the benefit of stopping on the pedal and instantly going instead of waiting for the motor to climb into its powerband.

 

I agree with some of the others here that there are other things to look at before changing gears - superchips, etc... I would change that advice if there was going to be a change in tire sizes to a much larger tire. Then a gear change is a no brainer. Many here think I'm crazy to run a 3:08 rear end, but for the driving I do, its exactly what I need. I pull off over 20 mpg all the time on the freeway doing 70-75 mph. The engine is only turning 1900 RPM's at 75 MPH. If I were serious into towing or looking for the off the line performance, higher gears would be nice.

A simple explanation of the gears would be that for every 1 turn of the axle, the driveshaft has to turn 3.08 times (in my case).

 

I think the thing to remember is that changing the gearing doesn't increase power like a chip or a exhaust system does, it just changes the engine speed for a given road speed. This power doesn't show up on a chassis dyno but it does show up on the ***-o-meter dyno.

In my case, the 4.10's put me closer to the torque peak at the speeds I drive. It makes the truck seem much more powerful, since it revs higher for a given speed than it did with the 3.55's. It makes a huge difference when towing my trailer.

I think the change was money well spent. My truck almost never downshifts to 3rd on the highway running solo and pulls my trailer way better. My fuel mileage difference is not noticeable. YMMV

Personally, I think Ford should offer 4.10's from the factory. My truck is too heavy for 3.55's with the ORP tires. Someone with a SB, Reg cab 4x2 would probably not need 4.10's with the little 16" tire package.

Ian

 

What size gears are in the Lightning's?

 

I have also ran my truck on the ***-o-meter dyno and have gotten wonderful results. The applied power of gears can only be understood when you have mashed the pedal in a truck that has gears, and until then, no amount of reading can make understand what they do and don't do.

The dodge off-roadster changes the 3.55's or 3.92's to the 4.10's to counter act for the 33" tires. Chevy also has and option of 4.10's for an additional $50. Does ford put them in the new off-road truck with the rancho's? I hope they had the brains to.