Gear change.....lower?????
 

Hello everyone.

I am getting ready for the gear swap from 3:73 to 3:45. I was talking with some "gearheads" at work the other day and they seem to think I will do better with 4:10's rather than 3:45's. I told them it may be better in town but I spend most of my time on the highway. They said "oh you'd be surprised."

I still think 3;45's are the way to go, but in an effort to try and learn something here, can someone explain to me why these guys think they are right with the 4:10's? I would think my poor little 2.3l would be turning way to many rpm's at 60 mph with such a low gear.

Thanks for trying to teach "non-mechanical" me something.

I like my 3.45 and my mileage is great with the .80 overdrive 5 speed. Maybe your friends just don't get 30+ mpg in a pickup truck. If I wanted a 4.10 I guess I could downshift two gears.

regards
Mech

Well, sure they'd think that 4.10:1 would be better. You'd practically give yourself whiplash whenever you'd accelerate from a dead stop, and your in-city fuel economy would improve a bit. Wouldn't do your highway fuel economy any good, though.

If you reach for advice outside the ecomodder community you aren't likely to receive the best advice. Tuning for max fuel economy is an extremely small niche relative to the power and speed group.

That being said, it's well documented here on EM that lower RPM at a certain speed = better fuel economy. For highway cruising you will want the tallest gearing that will work in your application.

I had someone tell me that a cold-air intake would improve my mileage. When I tried explaining a warm-air intake he essentially called me a heretic.

higher rpms = faster pulse
 

That is true for cruising, but the only difference with P&G is the pulse. Compared to a DX, my EX has higher rpm's, but also a faster pulse that results in a greater glide ratio.

I have noticed this in my Festiva. It doesn't do well at all at highway speeds, but low speed pulse and glide on back roads, I feel it's almost as good as any option.

They will also tell you you need a 9" rear end. Ignore them.

In my truck I can always choose a lower gear for the pulse.

3.73 to a 3.45 is not much difference, about 10% lower cruising RPM.

97 Ranger transmission ratios (Mazda transmission):
1st
2.47
2nd
1.87
3rd
1.47
4th
1.00
5th
.75

Basically at 3.00 rear end and a 4.00 rear end would be the same as 4th gear with the 3.00 and 5th with the 4.00.

I guess it takes too much effort for your friends to downshift if they want a higher overall final drive ratio. Personally I like the lower engine RPM on the highway, and if I am climbing a hill that I can't climb in 5th then just go down to 4th or 3rd.

Meanwhile I have a overall final drive ratio they do not have and they are paying for it every day they drive.

When I bought my Ranger I knew the transmission code for the rear axle and much to my delight it was the 3.45. The owners manual says to never jack up the rear end using a floor jack and the center of the rear axle. I wonder how many ranger rear axles have been ruined by those who never read that information.

regards
Mech

I agree with all of you. I thought maybe (by some weird twist of mechanics), if there was something to what they said I could learn something. I guess what I did learn was not to listen to listen to guys who like to go faster than farther. :)