Is 13MPG w/ Conservative Driving Possible?

[MichiganDiesel]

I just got a new to me '01 F250 7.3L. I know it's the nature of the beast to get poor mileage, and as much as I hate paying the prices, I will gladly continue to do so before I buy some compact car.

I'm a conservative driver and try to stay under 2000 RPM's except for like a freeway merge or something of the matter where I need more takeoff. Occasionally on the freeway I'll get my speed up to 75, but never anymore. On a typical day, I'll swallow my pride and chug along at 60-65 and get the extra MPG.

I do tow with my truck a lot during the summer, but the winter months I have no work for it and it's a grocery getter. My commute is short, and my truck is barely warmed up before I'm turning it off, which I know is a problem, and a cause to the lower MPG's, but I still set it out on the freeway quite often.

I added an Edge programmer (Evolution CTS) to monitor my gauges, so far I've had it off of the stock settings for less than 15 minutes and it's back again. I'm not into racing or the matters. I wanted it for the gauges. And as I look at the gauge it gives me max readings of 10-11MPG with cruise set at 55MPH. I'm a big coaster and it will bump up a little but not much. Taking off is even more sickening with the instantaneous gauge showing, and keeping the truck under 2000RPM's it doesn't hit double digits until I get up to 55MPH and set cruise.

Except for the programmer now, the truck is nearly 100% stock from what I can tell. 215,000 on her now. And for the record, I know the programmer has neither helped nor hurt the mileage, I had the truck for about a month and a half prior with similar mileage and decided to try the programmer as a effort to increase MPG's along with the gauges.

When I bought the truck the gauge read 17MPG, since it's dropped to 15.5. Calculating by hand (and using Fuelly) I'm getting about 13.5 MPG, which with people saying they get 17-19 normal driving and around 13 towing, is hard for me to understand what I'm missing. It's like I have pinhole in my tank or something!

Anyone in the same boat as me or know something that could help it out? I ride my F8000 with 3208 HARD come summer, things slow as a snail so I really have to get on it to get up to speed and it doesn't have much worse mileage than my F250...

[RT]

Something is seriously wrong with those numbers. I've never dropped to 13.5 even with a two car trailer.

Does your Edge allow you to monitor boost? How about EBP? Do you have a cat on yours? Any exhaust restrictions (crimped exhaust)? I'm sure you are fighting the winter fuel which gives worse MPG than summer blend, but those numbers are still horrific.

[INFRNL]

Your mileage will be down some due to winter fuel, but it shouldn't be that much. Could be a variety of things.
ie; ipr, icp, cps, ebps, ebpv sticking, etc.

[MichiganDiesel]

Glad I'm not going insane over this! Looks like I'll have to dig into it in greater depth.

What I do know:

I'm sure I'm running some sort of winter blend, but like you said, shouldn't be that big of a difference. And I've been running an additive, started with Diesel Kleen and recently switched to Opti Lube XPD, which should boost the cetane levels back too summer blends... I think.

I can measure boost and EBP with my Edge - I will set those gauges next time I hop in the truck and check them out.

Not sure about a cat., haven't looked. Will check it out.

The Edge can also measure EBP, I'll set that gauge as well and check some readings.

I've had 3 CPS's in it since I got the truck now. First was faulty, changed to the Duralast, jumped ship to the BW, had issues with stall with wipers, so back to the Duralast. Noticed no change in mileage.

Not familiar with IPR or ICP, what are they and how do I check them?

For the record, here is my Fuelly. I only just started using it because I thought I must be screwing up calculations by hand... I wasn't!
https://www.fuelly.com/driver/michig...uty?fu=3706260

Thanks for keeping my sanity check guys!

[INFRNL]

I just realized you are the same guy asking about cps' s, lol.
I would start by checking your exhaust back pressure sensor, they tend to get clogged. Also check the tube, they tend to crack, get clogged or get pin holes.

Icp is injection control pressure iirc. Its on the driverside head at the front of the valve cover. If you pull the connector off and it has oil in it; its on its way out and should be replaced.

Ipr is injector pressure regulator mounted on the back side of the high pressure oil pump.

Also check the valley to see if any oil or fuel has puddled up. Sometimes the fuel bowl drain will develop a leak.

Exhaust back pressure valve can also stick a bit causing issues. Easiest way is to unplug it and it should stay open. This might help.

Possibly brake calipers sticking creating a constant drag reducing mileage.
I think its a sensor, but im no expert.

Best of luck

[jricherson]

If you are using your tuner then it can mess up your readings on your Lie-O-Meter on the overhead console. The most accurate is filling up and keeping track of you miles and calculating yourself.

[delreyr]

I had a similiar problem with low MPG, had a front caliper that was sticking pretty bad, new calipers/rotors, smooth sailing now!! These trucks have a reputation for the caliper pins corrroding and not letting the caliper adjust/slide left to right.

DelRey

[JimmyDee]

I have gotten as high as 19.5 but only once. On the road driving conservative, 17-17.5 is usual in the summer time. Winter kill my mileage and if I do short trips, 13 is more the normal. Winter fuel and the cold seem to kill the great mileage you would expect with a diesel. I never let the truck run to warm up or for extended periods of time.
Winter time is hard on mileage.
Jim

[caryt]

MPG's varies...some trucks get better than others..even with the same options.
200k miles...I'd look at new inj's as they are getting old....a TS chip with custom tunes, exhaust and intake to get the best results..

Pm or email me if I can help with this.

Cary

[PSDForever]

Locked in hubs will decrease MPG. Do you have shift on fly or manual hubs?

Do you still have your door sticker on the driver's door showing your PCM code? My '01 had PMT1 from factory. Never was able to get above 13 driving in town. Had it re-flashed to PMT3 which was better. Bit better shifting also. May check underside of the hood and see if there's a sticker there from ford that they re-flashed it. Different codes in the PCM IMHO can cause differences in the MPG.

I'm pretty consistent with 17-18 now with BTS transmission, tunes from Brian as well, 4" exhaust, Banks (k&n) filter, higher temp thermostat, hubs unlocked and summer blend fuel.

As others stated, drag is your enemy, brakes, hubs, bigger tires, lift kits, winter fuel, exhaust restrictions.

Bottom line like said, fill up tank consistent each fill. Stand there for the additional 5 minutes and make sure you see fuel at the filler cap each fill up and then calculate your mileage by hand. Only true way to do it.

Do the in-tank mods and fix the vent tube inside the tank and you can fill up consistent everytime without the extra stand time at the pump.

Could be a sensor. Do you have access to anyone with a scanner?

Good luck.

[MichiganDiesel]

Originally Posted by INFRNL

I just realized you are the same guy asking about cps' s, lol.
I would start by checking your exhaust back pressure sensor, they tend to get clogged. Also check the tube, they tend to crack, get clogged or get pin holes.

Icp is injection control pressure iirc. Its on the driverside head at the front of the valve cover. If you pull the connector off and it has oil in it; its on its way out and should be replaced.

Ipr is injector pressure regulator mounted on the back side of the high pressure oil pump.

Also check the valley to see if any oil or fuel has puddled up. Sometimes the fuel bowl drain will develop a leak.

Exhaust back pressure valve can also stick a bit causing issues. Easiest way is to unplug it and it should stay open. This might help.

Possibly brake calipers sticking creating a constant drag reducing mileage.
I think its a sensor, but im no expert.

Best of luck

Yes, thanks. I originally thought I would try changing the CPS to see a mileage increase, no luck.

I see my Evolution has a gauge for the ICP, is there a range that it should be in? I was just looking in the manual, haven't yet tried it, am going to give it a nice run here shortly and check all the different readings.

My valley is extremely dirty and looks to be the home of a rat at one time, but no signs of oil.

There's also an EBP gauge on the Evolution, should I be in a range there as well? I take it that no back pressure valve means better mileage with saying unplug it and it will stay open? What are the down sides?

Originally Posted by jricherson

If you are using your tuner then it can mess up your readings on your Lie-O-Meter on the overhead console. The most accurate is filling up and keeping track of you miles and calculating yourself.

I have done all mileage calculations by hand. The trucks meter is giving me about 3.5 MPG better than what I'm getting.

Originally Posted by delreyr

I had a similiar problem with low MPG, had a front caliper that was sticking pretty bad, new calipers/rotors, smooth sailing now!! These trucks have a reputation for the caliper pins corrroding and not letting the caliper adjust/slide left to right.

DelRey

Wouldn't the calipers generate a lot of heat then? If they are warm after a trip down the road would they be worthy of replacement?

Originally Posted by JimmyDee

I have gotten as high as 19.5 but only once. On the road driving conservative, 17-17.5 is usual in the summer time. Winter kill my mileage and if I do short trips, 13 is more the normal. Winter fuel and the cold seem to kill the great mileage you would expect with a diesel. I never let the truck run to warm up or for extended periods of time.
Winter time is hard on mileage.
Jim

Much the same here, but even after a longer trip, and during our 60 degree days here a couple days ago, I didn't see a MPG spike. Maybe time will tell that it's just winter and it's not a fan.

Originally Posted by PSDForever

Locked in hubs will decrease MPG. Do you have shift on fly or manual hubs?

Do you still have your door sticker on the driver's door showing your PCM code? My '01 had PMT1 from factory. Never was able to get above 13 driving in town. Had it re-flashed to PMT3 which was better. Bit better shifting also. May check underside of the hood and see if there's a sticker there from ford that they re-flashed it. Different codes in the PCM IMHO can cause differences in the MPG.

I'm pretty consistent with 17-18 now with BTS transmission, tunes from Brian as well, 4" exhaust, Banks (k&n) filter, higher temp thermostat, hubs unlocked and summer blend fuel.

As others stated, drag is your enemy, brakes, hubs, bigger tires, lift kits, winter fuel, exhaust restrictions.

Bottom line like said, fill up tank consistent each fill. Stand there for the additional 5 minutes and make sure you see fuel at the filler cap each fill up and then calculate your mileage by hand. Only true way to do it.

Do the in-tank mods and fix the vent tube inside the tank and you can fill up consistent everytime without the extra stand time at the pump.

Could be a sensor. Do you have access to anyone with a scanner?

Good luck.

Wouldn't me having the Edge Evolution reflash the computer either way? I will look for a sticker though.

I have the Harley Davidson rims and tires on my truck that are found on the slightly newer models and although they are bigger, it's not a significan difference. No lift and a stock suspension.

I saw some posts and discussed about filling up the tank all the way. From my understanding, it would be about 5 gallons max extra. I can see where if I had a 10MPG calculation, then a 20MPG, the tanks were not filled each time, but with limited fluctuation I'm GUESSING, they are filling up to pretty much the same spot. And, although they aren't perfect, my fuel fill gauge always goes completely to full after I'm done filling. I do plan on starting to trickle some the rest in though.

I would still like to do the mod, I'll search around, but if anyone knows where a good demonstration is on how to do it, I would greatly appreciate it.

I don't have a scanner, what type of sensor would it be? Is it something my Evolution could read? It plugs into the same OBDII port. If not, where could I get one and how much would they run?

[badbart]

I run my truck with the programmer in #2 all the time. I get 10-13 mpg towing 6000-9000 lbs at 60-65 mph. I have driven it conservatively at 55 mph empty and got as much as 20.7 mpg. You got a problem.

[MichiganDiesel]

Okay, so I put some gauges on the evolution to check:

ICP: always stayed roughly 3/4 of what engine RPM is. (The Evolution automatically divides by 10 on the RPM's, so it's either 3/4 of true RPM, or 3/4 of a tenth)

Boost: I was still staying under 2000RPM's, but never saw a PSI over 2, not sure where it should be at, it wasn't any load, so I don't know if it should be higher. When at normal speeds, boost was 0.

EBP: Maxed out around 4 or 5, didn't give any units, so I don't know if that's in some sort of pressure or what.

Forgot to check and see if the front calipers were warm. Is there any better way I could check this?

I'll have some time over the weekend to really go through things if there's anything I need to check specifically on the truck, it would be greatly appreciated!

[RT]

For your boost, get on the entrance ramp and stomp on it - you should be able to generate 17- 20 psi. Lack of boost is a major killer of MPG.

[MichiganDiesel]

Originally Posted by RT

For your boost, get on the entrance ramp and stomp on it - you should be able to generate 17- 20 psi. Lack of boost is a major killer of MPG.

Got it, will do. Thanks.