My apologies for posting a second thread on a similar topic, however I need to place my order soon and this is the one choice I'm hung up on.

I learned from you guys that all of the F450s are speed limited at 81 MPH, due to the tires. This makes me think that perhaps I should just get the extra tow package with the 4.88s since the higher speed gains of the 4.30s are limited by the top end limit.

However I would like to know how the two gear setups compare in RPM at highway speeds? I've checked the various postings related to fuel economy, but it is difficult to get a true comparison based on differing conditions and driving patterns.

 

I'll try and get some on my truck tomorrow. (4.88's)

 

I am not sure what you are looking for but I have 4.88's. In Montana I am sure you will be hitting the speed limiter quite often. At 80 mph I am running +/-2850 rpm.

 

Hey there! I have a 2004 F450 4X4 crew cab dually, at 65 mph I'm at 2200(approx). I think this truck gets better mpg, than my previous one (1997 F350 DRW Supercab, w/ 7.3 E4od and Gearvendor over/under). I have a trip coming up and will try to log the mpg. Now I know why it's speed limited to 82 mph. The tires! Keep on truckin! DALEDIESEL.

 

1750 rpm is 48mph
2000 rpm is 55mph
2250 rpm is 62mph

Didn't have an area yet to do the others, but it should be

2500 rpm is 69
2750 is 76
3000 is 83

Thats if it doesnt get some slip at the higher speeds.

 

Thanks a bunch. You guys are really helpful. I don't order one of these everyday and I don't want to screw it up. Y'all are giving me the confidence that I'm getting the right equipment.