Regearing transmission 5th gear?

[echo-francis]

no offense but you guys are wrong with the ''you will burn more gas if you lower your gear ratio because your engine will work harder''

lets take a look a some trans really built for fuel economy.

92-95 Civic CX/VX 1) 3.250 2) 1.761 3) 1.066 4) 0.853) 5) 0.702 final) 3.250

00-06 honda insight 1) 3.461 2) 1.750 3) 1.096 4) 0.857 5) 0.710 final) 3.208

those cars have less power then ours and there are more exemples of cars like that

and if you look at bsfc maps you will understand that a engine working harder is more efficient

[CrankyOldMan]

Originally Posted by echo-francis

no offense but you guys are wrong with the ''you will burn more gas if you lower your gear ratio because your engine will work harder''

lets take a look a some trans really built for fuel economy.

92-95 Civic CX/VX 1) 3.250 2) 1.761 3) 1.066 4) 0.853) 5) 0.702 final) 3.250

00-06 honda insight 1) 3.461 2) 1.750 3) 1.096 4) 0.857 5) 0.710 final) 3.208

those cars have less power then ours and there are more exemples of cars like that

and if you look at bsfc maps you will understand that a engine working harder is more efficient

I'll keep an eye on my Scangauge the next time I'm on the freeway, but I'm pretty sure that fuel economy starts to decrease after about 3500 rpm. I've got the 4.3 final drive and .725 5th ratios, specifically to keep the freeway rpms in a more reasonable range than the .815 stock. There is an optimum point for efficiency, and it's not a linear relationship to rpm and speed. Wind resistance plays a huge role in efficiency.

[fnkngrv]

Originally Posted by echo-francis

no offense but you guys are wrong with the ''you will burn more gas if you lower your gear ratio because your engine will work harder''

lets take a look a some trans really built for fuel economy.

92-95 Civic CX/VX 1) 3.250 2) 1.761 3) 1.066 4) 0.853) 5) 0.702 final) 3.250

00-06 honda insight 1) 3.461 2) 1.750 3) 1.096 4) 0.857 5) 0.710 final) 3.208

those cars have less power then ours and there are more exemples of cars like that

and if you look at bsfc maps you will understand that a engine working harder is more efficient

You are trying to compare apples to oranges here. regardless of what the numbers sheets say the platform makes a dramatic difference in real world experience. This is just as you really can't compare the LB and the sedan when making adjustments to the trans and anything having to do with speed. power, and economy as they have different drag coefficients as well as aerodynamics in general to include center of balance/stance. I have been doing a lot of research for a converse reason which is to enable me to obtain a higher top speed. Man it really is looking seriously like I would have to pour thousands into a totally custom gearbox with custom fabbed gears as well.