Rear End Ratio

[MustangMike]

Have a question. I am stuck between choosing the 4.10 ratio or the 4.30 ratio (F250 V-10 4X4). I have seen this topic discussed before, but having a hard time making a decision.

I tow about a 7000 lbs trailer about once a month. Most of my driving will be short trips to and from work (short is under 15 miles). The rest of the time will be used running around town in stop and go traffic with weekend roundtrip drives of 180 miles.

The 4.30 ratio would be best in a 4X4 for towing but I do not tow that often. The 4.10 may provide me a little more gas mileage. Now, I am not buying this truck for gas mileage (my wife’s Focus is for that), but if you had a choice, what would you recommend based on the above?

Also, since I drive several 180-mile weekend trips, what rpm does your stock F250 FX4 4.10 or 4.30 truck register when going 65-70 mph (please note your tire size)?

I plan to talk with the dealer and test drive a few, but do not find many V-10 powered rigs to compare. I have made gear swaps on Mustangs and it is always more expensive doing it after the fact.

Thanks

[todlake]

Mike,

The 4:10s will be plenty adequate for what you're describing. BUT, if you have any intentions of going with larger tires down the road, get the 4:30s. I have 3:73s which have been great on fuel economy (as high as 16.5 hwy), but when I get the urge to put on some bigger rubber, I just think about what will happen to my fuel milage and towing power. Just my .02

Robb [img]/ubbthreads/images/graemlins/grin.gif[/img]

[shark1955]

My previous truck was a 2001 F350 4x4 V-10 auto with the 4.30 LS rear end. I used this truck to pull an 11K 5th wheel camper. This truck had plenty of power to spare and had no trouble maintaining the speedlimit on the freeway pulling the 5th wheel. I would stay with the 4.10 if you don't plan on getting a heavier trailer or don't tow in hilly terain. The 4.10 will give you plenty of towing power for a 7k pound trailer. For the extra cost I would get a 350 instead of the 250. The 350 has the same front suspension but a greater payload capacity rating on the rear axle.

You probably won't find a SD with the V10/4.30 combo on a lot. I had to order my 01. When I was shopping for my current truck my 1st choice was that combo. I ended up with the diesel because that was all that was on the lot and it had a $3k rebate.

[MustangMike]

Thanks To_D_Lake and shark1955.

I have no plans to put larger tires or pull a bigger trailer. I pull this trailer now with an 302 V-8 F150 with a 3.73 gear (truck now has 187000 miles). It pulls it slow but fine. I don't win any speed races with the F150, but can roll on the freeway at 55-60 mph no problem. Think I will stick with the 4.10.

[toalpi]

What percent of your total running/driving time will be lightly loaded at speeds above 65mph? That is the only time that the 4.10s will be slightly more fuel efficient than the 4.30s. The 4.30s could be better for most of the other miles getting the truck up to speed with more leverage and staying in overdrive without down shifting as often in the 40+ mph range.

[robsd]

Yep as Todd said, bigger tires will negate any 4:10 you get. With 315's my 3.73 is probably a 3:50 or lower. I'm sure someone has done the calculation.

[BretMS]

Based on what you described, I would go with the 4.10 if you plan on adding larger tires, or the 3.73 if staying stock. The only reason to have a 4.30 ratio is for serious pulling near the maximum limits of the trucks capability or if you live in the mountains.