ytownls1

im debating on what to get, from reading the 3.73 really wont change my mpg much in my a4....but if i get 4.10s instead will my gas mileage be much different then the 3.73s?

I have the stock 3.23 GU5 right now and stock 10 bolt. when i get my gears will my stock 10 bolt be fine.....I really dont plan on getting much but lt headers, tsp catback, lid, gears, for this summer.

What gear brand will be the best for my car 1999 z28....after everything is installed im going to get it dynoed and either a frost tune or hp tuner then look at the huge hole in my wallet

MR01Z28

Yeah I am thinking the same thing. Any info would be great

Tobias05

iTrader: (1)

spend the money on a stall first. you'll get the seat of the pants you're looking for, and without absolutely neutering your MPG.

I have 3.42s and an Edge 3200 stall in my 87. Great performance without going over the top. Typically cruise at about 2200 RPMs around 70 on the highway. Awesome around town manners, loves to rev and pull from stoplight to stoplight.

jc98ss

iTrader: (13)

don't get 4.10's in an A4, you'll hate life after that.....3.73's are the lowest i'd go (highest number).....+1 on the stall, it's a huge upgrade for the auto guys.....Richmond gears suck, Motive's are ok, AAM gears (factory GM gears) are said to be the quietest, that's what i'm getting when i put 4.10's behind my M6

1999Z28

Everyone who says 4.10s for an auto are too much usually never drove one. I had 4.10s in mine and loved it. I'd say if it's a bolt on car 4.10s are the way to go, but if you're doing heads and cam and stuff then you'll run outa 3rd gear. 3rd gear ends around 110 with the 4.10s. Mine still pulled hard in 4th tho, I had it to 145mph at about 5500 rpms. But who goes that fast ever anyways.

I just swapped to a 6 speed in my car and it's different having 1st gear go to 45mph instead of 30mph. But I did slap 28" tires on it too.

Maroboy

iTrader: (1)

3.42s or 3.73s..

FirstYrLS1Z

iTrader: (4)

^^^ agree with post #5 in that those who say 4.10s' are too much have never driven one. I'm 4.56s'/A4/TCI 2800 ( I do have a Yank SS3600 waiting to be put in). and the responsesiveness is incredible. !st & 2nd are wicked and 4.56/2800 cause it to get into the power band VERY quickly. 4.56s' are too much for the 1/4 mile,so I would not go over 4.10s'. 3.73s' with a 3600 are an all around good combination for driveability,power,& mpg.

ytownls1

ok so with my gears 'should i' or 'do i' need a stall???

right now i have amazing gas mileage 'for a v8' i get about 330-350 miles on a tank of gas on the highway and 220-245miles in the city.

so im really hopeing that doesnt drop too badly..

but how many people here have an a4 and 4.10 whats your rpms like on the highway? I cruise with radar on between 75-85...since no1 yet mentioned about the stock 10 bolt im guessing ill be fine till next year when i want a pro charger

fccs

iTrader: (26)

3.73's for A4's, 4.10's for M6's.

MidwestChassis

iTrader: (5)

If someone is looking to try a inexpensive 4.10 I have one left on the shelf I would blow out the door cheap. It is a standard ring not a thick so keep that in mind. It is new in the box unused off brand that we purchased for a local customer and then they changed ratios. Figured I would offer it up before I sent it back.

I would sell it for $135 plus shipping.

An to add, gear ratio depends on what you want from the vehicle. Other things that need to be known is HP level, how many RPM'S do you plan on turning, tire size, and type of power adder if any in the future.

If you have a N/A combo and plan on running a 28" slick a 4.10 would be a good drag racing gear. In OD you should be turning minimal RPM'S while street driving.

1999Z28

with my 4.10s in my auto
60 was 2300
70 was 2700
80 was 3000

look at my time in my signature tho, it ran incredible for just headers and gears.
Only time I calculated my gas mileage all highway was a 70 mile trip i stayed at 80 the whole way and only got 18 mpg. But i'd imagine you could easily do 24ish if you stayed around 60.
My car isn't a daily driver and I just do a lot of around town stuff.

ytownls1

is that in drive or over drive

justin hover

Man...3:73s are all your gonna need...With our a4s agrressive first gear, if you get 4:10s you simply won't hook...you won't...kiss first gear goodbye when giving it gas, unless you add slicks, and really shorten your rears life. You have to baby the throttle enough with 73s in 1st to get the most out of the gears as it is.
Pulls 2x better than stock, 1900rpm at 55mph, not a huge hit in gas, and with a tune, just get the 3:73s. Theirs a reason you'll get a 20 to 5 vote on 3:73s over 4:10s...

Since I went from 2:73s to 3:73s, I wanted to drive it like this for a year for a whole new feeling, then next year will be the 3600 stall for another whole new feeling. So either way