[tire]

Originally Posted by I Am Cornholio

Know this thread is old, but 4K rpm at 60 is plain BS. The '04 V6 auto in my driveway with 4.10s doesn't hit 3000 rpm until just below 80 mph.

All the stories commonly heard about 4.10s killing highway mileage is also BS.

yes on the first, no on the second.

my '00 v6 5spd w/ 4.10's was somewhere around 2,800rpms@ 65-67mph if memory serves. if i'm mistaken it's not off by more than a couple mph. i typically cruised at 2,500rpms which was just above 60, once again, if memory serves. 3.73's on an auto v6 is a little conservative IMO, but some would say 4.10's on a 5spd is too much. if you run around at 70mph or faster on the highway you WILL kill your mileage bigtime. cruising around like a low rider didn't change my city mpg, it may have actually helped (negligibly).

austin

[drawlin]

auto's tend to do better with 4.10's. we have a bigger(or lower) OD.

[I Am Cornholio]

Originally Posted by tire

yes on the first, no on the second.

my '00 v6 5spd w/ 4.10's was somewhere around 2,800rpms@ 65-67mph if memory serves. if i'm mistaken it's not off by more than a couple mph. i typically cruised at 2,500rpms which was just above 60, once again, if memory serves. 3.73's on an auto v6 is a little conservative IMO, but some would say 4.10's on a 5spd is too much. if you run around at 70mph or faster on the highway you WILL kill your mileage bigtime. cruising around like a low rider didn't change my city mpg, it may have actually helped (negligibly).

austin

No, cruising at highway speeds of up to 80 mph on road trips HAS NOT killed mileage bigtime or even small time.

[311-420]

Originally Posted by I Am Cornholio

No, cruising at highway speeds of up to 80 mph on road trips HAS NOT killed mileage bigtime or even small time.

whether or not you think it has hurt your mileage, it has. its quite simple really, to make more rpms you have to have more fuel

[I Am Cornholio]

It's not quite that simple but believe as you wish.

[311-420]

Originally Posted by I Am Cornholio

It's not quite that simple but believe as you wish.

its not? how about you enlighten every single person on this site who apparently doesnt know how to make rpms without fuel

[95 GTS]

Originally Posted by drawlin

now try it with over drive off. in heavy rain/slick roads, i drive with OD off. your rpms will be around 4k at 60 with od off, or at least that what i calcualted by useing the gearing numbers.

with od on, yeah, 4.10's wont be so bad, if you dont mind the engine hum.

thats because you are not smart and apparently dont know what you are doing with your transmission.

spreading poor info like you did has a mal effect on peopel asking questions trying to learn.


also there is a misnomer about geras effecting gas mileage greatly.

Your right foot dictates gas milage more than your gears do. RPM is not a direct relation to gas mileage, in fact, going too low of an rpm on the highway can hurt your gas mileage depending on the powerband.... Hmm why do hondas cruise at 3k+ and tauruses cruise at 2500+ at 70 mph. It is more efficient.

A v6 is nothing like a gt, it does NOT have low end grunt to drag your heavy car along at 1800 rpm.

increased gear will actually increase your in town gas mileage in town for many cars and driving styles.. now if you are in the throttle way more enjoying the new increased tractive effort of the gears, that is a different story. Yes you will cruise higher in rpms, but your car makes mre power the higher you go thus requiring less throttle application to maintain speed.

A car requires the same HP to maintain its cruising speed at a given curb weight, NO MATTER what. Car still needs the same amout of fuel to make the needed 13-20 hp (ex.), some times even less with a higher gear if it is more efficient where you drive, some times a lil more. It is never a drastic change from 25 mph to 17 like some people will spout on the internet. With my gears and my cam, My car gets best gas mileage above 80+ on the highway. This is due to my combo being more efficient as the cam reaches it's power band.

People who drive cobras with 4.56 gears can still get low-mid 20s on the highway. Nighthawk got over 300 miles on tanks with his 4.30s in his GT. I got 360 to a tank with a 290 pound passenger and a complete gt40p longblock in my trunk and back seat with 3.73s. This was driving to Katy and back so I got the up hill and the down hill route.

It is the driver that kills mileage, not the just the gears.

[superman]

I have been thinking about putting 3.55s in the wifes 97 V6 Automatic. It has 2.73s in it right now. The reason for the 3.55s is that I already have the 8.8 rearend. What would I have to change to get the 3.55s to work? Any issues that I should be worried about?

[95 GTS]

Originally Posted by drawlin

if its a daily driver, 3.73's are perfect. 4.10's are gona jump ur rpm's at 60 to about 4k.

Orily? Is this what YOUR car does at 60 with the 4.10s that are in it?

[95 GTS]

Originally Posted by 311-420

whether or not you think it has hurt your mileage, it has. its quite simple really, to make more rpms you have to have more fuel

thats why there are tons of mach 1s rolling around with 4.30s getting 25 mpg on the highway

Your mileage changes because your foot is heavier plain and simple.

and who the hell drives around in 3rd gear in their auto at 60? WTH is going through your head? not an attack, an honest question. PLease explain your idiocentricies and why you are 4k before you spout off a factoid that someone reads and takes as truth.

[95 GTS]

Originally Posted by superman

I have been thinking about putting 3.55s in the wifes 97 V6 Automatic. It has 2.73s in it right now. The reason for the 3.55s is that I already have the 8.8 rearend. What would I have to change to get the 3.55s to work? Any issues that I should be worried about?

just the speedo calibration for the car.

[superman]

Originally Posted by 95 GTS

just the speedo calibration for the car.

What would that consist of? Sorry for the dumb question, I am used to working on the older fox body stangs.

[95 GTS]

you will need the gear with the correct number of teeth or a speed cal if your output is digital. you can find them used or new fomr dallas mustang.

[ImMeNukka]

so basically the moral of this story is everything thinks 3.73's are better than 4.10s? sory for the dumb question i was just curious too.. and i mean i did read everything ya'll said but truthfully its like all jibberish to me haha maybe someone can help me n explain some of the stuff to me?

[I Am Cornholio]

Resurrection of a moldy thread......

Don't be scared away from 4.10's. 3.73's may be adequate, but you'll regret it if you don't go ahead and get 4.10's (and a limited-slip differential) while you're in there.

[ImMeNukka]

mmhmm.. so im pretty sure im gettin the 4.10's.. but along with that u think i should get t-lok right? n what exactly does this do.. sorry for the dumb question again im just tryin to learn u know? lol

[I Am Cornholio]

A T-Lok applies traction to both rear wheels at the same time, unlike the stock open differential in the V6 which applies traction to only one rear wheel. With 4.10's on an open differential, you will be much more likely to spin one rear tire during "spirited" takeoffs from a stop rather than launching effectively.

[bandit]

I have 4.10's and t-lok on my V6. gas mileage isn't too bad as long as you don't drive crazy all the time.

[Beck]

Originally Posted by bandit

I have 4.10's and t-lok on my V6. gas mileage isn't too bad as long as you don't drive crazy all the time.

big difference / worth it jeff?

[ImMeNukka]

ooooooo i see i see well u learn somethin new everyday n thanx for teachin it to me! .. now... where r some good sites to get the 4.10's and t-lok from? for a 94 mustang auto that is..