4.10 or 4.30
Logistics Pro
Joined: Feb 2000
Posts: 3,955
Likes: 50
From: Mesa
Well here ya go... http://www.4lo.com/4LoCalc.htm
All figures are at 65mph, in overdrive, .70 OD ratio
A stock F250 comes with a 265/70R17 tire which is 31.6" in diameter. With a 4.10 gear, the rpms are 1984. With a 4.30 gear it's 2028rpms. If you want the rpms of the 4.10 gear but you have the 4.30 gear then using 33.1" tall tires will bring the rpm to 1986.
The optional 275/70R18 tire (standard on the F350) is 33.1" in diameter. With the 4.10 gear rpm is 1893. With the 4.30 gear rpm is 1986. In this case, a 35" tall tire will have 1878rpms with 4.30 gears which is a hair lower than the 4.10/33.1" combo.
Confused yet?
So, if you order an F250 with 4.30 gears and the 275/70R18 tires it will be the same as an F250 with 4.10 gears and 265/70R17 tires. Or, add 35" tall tires w/4.30 gears and you'd be close to the same rpms as having 4.10 gears and 33.1" tires. The best towing combo would be a 4.30 gear and the 265/70R17 tire.
All figures are at 65mph, in overdrive, .70 OD ratio
A stock F250 comes with a 265/70R17 tire which is 31.6" in diameter. With a 4.10 gear, the rpms are 1984. With a 4.30 gear it's 2028rpms. If you want the rpms of the 4.10 gear but you have the 4.30 gear then using 33.1" tall tires will bring the rpm to 1986.
The optional 275/70R18 tire (standard on the F350) is 33.1" in diameter. With the 4.10 gear rpm is 1893. With the 4.30 gear rpm is 1986. In this case, a 35" tall tire will have 1878rpms with 4.30 gears which is a hair lower than the 4.10/33.1" combo.
Confused yet?
So, if you order an F250 with 4.30 gears and the 275/70R18 tires it will be the same as an F250 with 4.10 gears and 265/70R17 tires. Or, add 35" tall tires w/4.30 gears and you'd be close to the same rpms as having 4.10 gears and 33.1" tires. The best towing combo would be a 4.30 gear and the 265/70R17 tire.
Last edited by V10man; Mar 21, 2006 at 04:10 AM.
Guest
Joined: Nov 2004
Posts: 7,988
Likes: 55
From: north west new jersey
Originally Posted by shelters
Going to order a new F350 dually with v10. Trying to decide on 4.10 or 4.30?
Tow a utility trailer about 10,000 lbs. Thinking of going larger.
Any suggestions? Leaning towards the 4.10.
Gas mileage any different?
Will the engine rev alot higher at highway speeds with the 4.30?
Thanks
Tow a utility trailer about 10,000 lbs. Thinking of going larger.
Any suggestions? Leaning towards the 4.10.
Gas mileage any different?
Will the engine rev alot higher at highway speeds with the 4.30?
Thanks
Cargo Master
Joined: Nov 2005
Posts: 2,051
Likes: 10
From: TEXAS
I have the 4:30 in my F-450 PSD and love it. Low end grunt is fantastic. But I do tow alot. I did notice going from the old truck with 4:10 to 4:30 I did loss some MPG.
You could always go with the 4:10 and if unhappy change out the rear end. The cost to do so shouldn't be much more than the option cost to upgrade. You could also offset the cost by selling the ring and pinion gears that you take out to install the new ratio.
Just a thought.
You could always go with the 4:10 and if unhappy change out the rear end. The cost to do so shouldn't be much more than the option cost to upgrade. You could also offset the cost by selling the ring and pinion gears that you take out to install the new ratio.
Just a thought.
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