New member needs help

[Swingblade6]

Aloha everyone. I'm new to diesels & this board. Need advice (long)

Recently purchased '01 7.3 f250 4X4 cc sb w/68k miles & am very dissappointed in both towing power & fuel economy and would appreciate some input. Not sure of true weight but boat & trailer prbly are in the 8.5k# - 11k# range depending on fuel, gear etc. Truck did not have gauges but have ordered a pillar mount pyro, tranny, boost set up. I have changed oil & filter (full synthetic), checked trans fluid (ok), chnged fuel filter, added Diesel Kleen to full tank of fuel, airraid intake (filter is acceptable, ordering new one - feed tube clean). Haven't checked the turbo yet but will, don't think thats the prblm since no white smoke or hesitations and it spools fine.

Truck is chipped but don't know with what. 8-10" lift running Toyo 38's. Custom front susp' with coil over shocks, springs w/ small dbl wedge block & airride rear, rear hitch. Oversized transmission pan & rear diff' cover. Thank God for a custom 55gal tank. Other than fuel mileage & towing on grades truck runs strong with no smoke, hesitation, or other signs of a prblm.

Driving painfully conservative at all points (I mean that - I am 50 yrs old), Fwy mileage MAYBE 15 / intown 13 / towing 9. Towing 6% grades brought me down to 35miles hr & slight grades to 55-60 (I am not flooring it but close enough). Truck does not want to downshift under load unless I forced it to even in tow mode. From what I've read on here that is below acceptable. Have friend '06 6.0 PSD cc sb with similar set up - lift, tires etc -no chip but only 25k miles who pulled the boat to mexico - he breezed those grades at 75-80mph & altho I don't know his actual fuel economy he says didn't drop it much off unloaded.

My reading here leads me to believe it's the stock gearing with the 38 tires but then why does a similarly unchipped stock '06 - 6.0 PSD pulling same load & grade make me look like a 2 horse logging cart. Stating that my biggest priorities are towing power & then fuel mileage, am I on track here? If that's so what gearing recommended for daily road use & towing? Best online source for such gearing front & rear? Or maybe it's something else, any other suggestions? Any qualified assistance is much appreciated.

[ABOBB]

Welcome to Powerstroke.org

I'm not a tech, so I'll bump this up for ya.

I would guess however, that gearing may have something to do with this.

I noticed you didn't mention the gearing for either truck.

[Swingblade6]

Gearing on both is stock. 3.73 I believe

[RedMule]

The tires and lift I'm sure are not helping either power of mileage. I think I'd wait and see what the guages say when you get them installed and then report back.