[stagevi]

i currently own a 94 GT with a 5 speed and a 3.73 and some other mods. i am looking for a 99-02 cobra. my first mods will be gears and exhaust of course. i noticed that alot of cobra owners go with 4.30 or 4.56. are these surface street only cars or can/are they driven on the highway? i know the 4 valve is a much higher revving motor than a 5 liter. is this why 4.30+ is streetable? i am at 2300rpm in 5th at 75mph in my 94 and gas mileage is good. i would love to drive 4.30s around everyday but am wondering about gas mileage because i commute to work and school 25+ miles away. any response would be appreciated. thanks.

[Nate14120]

4.30's are fine, I'm not considering 4.10's in my 97 cobra. I may even get 4.56's. Yeah, the cobras don't red line until 6800. With any of those gears, you won't be about 3k on the highway. Probaly more mid to upper 2k

[PGreenSVT]

I run 410's with 26.1 inch 255/45/17's and clock in at 3k at 80mph. Don't know about anything slower. I can't get the car down there. Mixed Highway/City yeilds me about 19 or 20 MPG. If you do a lot of highway driving I would consider the 410's. I am also thinking about going to 430's with a 27 inch rear tire. Hope that helps.

Mitch

[Firme]

99-01 Cobra... stock tires dimensions...

at 75 mph

w\ 3.27 (stock gears) ~2150rpm
w\ 3.73 ~2453rpm
w\ 4.10 ~2696rpm
w\ 4.30 ~2828rpm
w\ 4.56 ~2999rpm

[stagevi]

would cruising at 2600-3000 rpm at 75 mph be horrible on gas? is 3000 rpm cruising overly high for the 4 valve? i know a cruising 3000 rpm on my 5 liter would kill gas and eventually some other things. 3000 rpm is more than halfway to redline on a 5 liter. is cruising rpm to speed relative to a 4 valve because of the higher redline? i don't know if i worded that right. thanks.

[Firme]

Originally Posted by stagevi

would cruising at 2600-3000 rpm at 75 mph be horrible on gas? is 3000 rpm cruising overly high for the 4 valve? i know a cruising 3000 rpm on my 5 liter would kill gas and eventually some other things. 3000 rpm is more than halfway to redline on a 5 liter. is cruising rpm to speed relative to a 4 valve because of the higher redline? i don't know if i worded that right. thanks.

well, I have stock 3.27's and have cruised ~90 many a times for a good lenght of time... which puts me at about 2600.. the engine loves it..no problems

the DOHC loves to rev...

I would say get some amsoil (lowest wear out of any oil) and cruise on..

[20Cobra01]

I cruised at 80mph from Pittsburgh to Carlisle for all Ford nationals and got 21 going out and 22 coming back. That was with 4 people and full of luggage. With four tunnels and two other cars in the pack I definetly was on the gas quite a bit.

[98cammer]

I have a 98 cobra with 4.10s and i drove from Indiana Ohio line to St Louis this summer running 70-75 on cruse and st got like 30mpg. I had to check it twice I was shocked