stangman
15 Year Member
jrc_03_gt said:
c2see21 said:i'm not lying
in all seriousness. both times i've put in 4.10's my milage went up. there is no way to prove it exactly, but i'll try to explain it. ford has a optimum performance range in the rpm band. well they gear the car so that when you hit 5th & cruise it's below that optimum range, baisically so their emissions are better. now when you go from 3.27's to 4.10's the engine isn't working as hard to keep the rev's up when you're cruising, cause it's better in it's power band. therefore making the engine actually more fuel efficent, but efficient emissions are sacrificed
XtorT'r said:Did you ever adjust your speedo after installing the 4.10's. 4.10's should have the effect of having smaller tires. you wouldn't get better milage speed for speed. If you didn't adjust the Speedo than your putting exta miles on your car that your not driving in addition to not knowing how fast you are really going. by the way the optimum range thing sounds like total bs when your traveling at 30mph(60mph, 100mph.. what ever) and your rpm's are higher than when you had stock ratio, you are burning more fuel. Emissions is seperate from milage, it just means your burning cleaner.