SO whats the deal with 12.5-13MPG?

[monoloco]

I have a 2000 f350 4x4 supercab stock except for an AFE intake and I routinely get 17 mpg. If I drive like granny and coast on the downhills I have coaxed it up to 19.9.

[nccatfan]

My old '94 made avg. 12mpg and it had 4:10 gearing on stock tires (4x2). My '99 on 33" tire and stock 3:73 gearing (4x4) makes mid-15mpg with no engine mods. '94 - 2700rpm=75mph... '99 - 2300rpm=75mph. Aggressive tires will pull mileage too. Was getting hi-17mpg on stock tires... dropped when I installed the 33" Nitto Mud Grapplers. Gonna go back to an all-terrain tire next (same size).

[AlaskanEngineer]

First of all, my truck drops mileage horribly going anything over 65 - over 65 you get 15.5 to 16

Under 65 I can easily get 18 on highway trips in hill/mountain country.

What are your typical cruising EGT's? Typical Boost Numbers? You might consider looking for a boost leak as that was stealing some of my power and reducing my mileage....

also +1 on getting a DP or TW chip. I have the DP and highly recommend it! I am positive the TW is excellent too from having talked to other folks here...

[stroken04]

Originally Posted by robertk

Ok well it seems liek some here think there 7.3 gets over 20MPG? I am lucky with no load to get 13 MPG with about 50-50 hwy / city.

I have a 01 7.3 2wd auto 35" tire, regeared (4.10) back to bring it back to stock final output ratio, that was about all and was getting the 13max.

installed 4" complete turbo back, new aem or something cold air box/filter, hypertech max mpg programmer, new fuel filter, and alignment. no real change maybe .25mpg.

had the CPS recall done about 4 months ago (the previous owner didnt ever have it done) and that raised it maybe 1mpg.

so what causes such bad MPG? It doesnt smoke at all when cruising and when you floor it, it will smoke some, but nothing like then I had the DP tuner or other diesels. Idles slightly rough but doesnt seem to miss a beat and for a huge diesel motor I figure its typical.

I take MPG by filling up till I can see the fuel level in the filler neck at max. then when its close to empty I refill to same location. Taking the total miles I have since last fill up and dividing by total gals I just filled up with.

the only thing I can think of is that the gearing if back at stock would use more of the enourmos torque this motor has for dead stop accel. and cruising speeds the motor would work less. but the finial drive ratio is back at stock.

The speedo has been calibrated using the hypertec programmer, so the miles part of the MPG is right.

So whats the deal? how do some claim over 20mpg and typ like 18 for some? is that BS or do I have something wrong?

If I have a issue where do I start? I have a killer ext warranty, but I have to call in the issue I am having first and diag is not covered if the repair item isnt covered or they dont find something wrong. Which is why I dont just take it in. You know ford will tell me aww its fine. or that its this little hose that isnt covered.

But if I can get some things to check and I can find out how to check them, I will take it to a local here and have him repair it and it will be covered. its a game with even the best ext warr's...

thanks
oh I do drive somewhat agressive but not overly. I typically will use about 2100-2300rpm (about 7-9psi) till about 25mph then down to 1700rpm (3-5psi) or so till speed limit is reached.

I didnt think the hypertech had the ability to change the spedo calibration. I though you could only do it with a "truspeed" or something similar

TruSpeed™ Speed Sensor Recalibrator · Superlift · www.superlift.com

[robertk]

Originally Posted by stroken04

I didnt think the hypertech had the ability to change the spedo calibration. I though you could only do it with a "truspeed" or something similar

TruSpeed™ Speed Sensor Recalibrator · Superlift · www.superlift.com

Well the hypertec allows for gear changes and tire size changes up to a 33. so it takes some math with the 35 to compinsate it in to the gearing you select. I know its within a MPH or 2 at about 45mph (mumerous radar traps tell me so as does the alpine navi). so its more accurate then prolly 75% of all other veh. out there.

As for the tuner. read my last post...

As for the boost numbers read my first post.

as for egt, those are up and down like a roller coaster from 0-45mph they go up to less then 800ish then down at shift, then up for the next gear some, then again and repeat... towing 7000lbs behind a 7500lbs rig on 35's and about 400-1000lbs in side = 1300deg max up our biggest longest hills here in so cali (grape vine and devore). and typ is about 10-1100 up moderate long hills.

boost max = 22psi and stead and no bouncing or jumping. so dont think theres a boost leak, but I guess there could be?

[ocrush]

My guess would be the tires, I swapped out the factory tires for a skinner profile larger height tire for use in the winter(blizzacks) and noticed a drop in mileage 265/70/16s (stock) compared to 235/85/16s (winters). As soon as I put back the stock size when the weather broke, I was back up to 16.5-17.5 mpg city (using cooking oil bio diesel)

[caryt]

Originally Posted by robertk

I tried a DP and was told the TW design and such was the same (yeah tuning might be slight bit different) and with the DP I was having major PATS issues. after 2 or maybe 3 (I forget but it was over a period of 4 months) I tried and they tried to get it right and just couldnt. It was overly embaressing to try and explain to those at the car wash, valet parking, dealer, friends, wife, etc. that it wont start when you try and you have to cycle the key fast or slow and hope that the theft light goes out, then you can start it. not to mention my top of the line Viper alarm would not auto start or turbo time.

Don't give up..difference between a DP and a TW..its the tunesand free reburns!

[bryceba]

Believe me or not I just got 20.5 the last 2 times I have driven to vegas which was the last two weekends. I actually drive around 85-90 the whole way. I know people wont belive me at all but its true. Verified it with GPS for speed and miles traveled

[bryceba]

Sorry I didnt realize this was an EX forum. For what its worth though my Moms gets 1 mpg less and its an EX with the same setup

[robertk]

Originally Posted by bryceba

Sorry I didnt realize this was an EX forum. For what its worth though my Moms gets 1 mpg less and its an EX with the same setup

wow only one MPG less with about 1000lbs more?