What are some common problems for the SD's suffering fuel milage loss? His truck is a 99 F350 SRW 2wd with only 107,000 miles (and i think a manual?). He says he is only getting about 15 mpg with his chip in economy mode, and it was worse before he bought the chip. I don't where he got the chip, but he said its a 6-position.

I was thinking he should check for a plugged cat, stuck closed EBPV, and maybe a very clogged air filter. What other things should he check?

 

Oil fresh & full & air filter - Also are cac boots tight. Uppipe leaks also can be leaking. Look for carbon. Boost leaks will kill power & gas mileage. These are a few easy things to check.

 

Another easy check is the EBP sensor on the front of the motor. It may be full of carbon and causing some issues. Also, it wouldn't hurt to clean out the EBP tube as well. Here is a YouTube video on it.


Not sure if it worked, but I tried.

 

if he has any sticking caliper slide pins, that will really take the mpg down. also have him run some diesel kleen fuel additive (grey bottle) through it. will help clean things up on the inside a little.

 

Everything that was mentioned previously, along with the obvious tire pressure,alignment,loaded or unloaded. I assume your talking hwy mpg not city. If city that's about normal. If hwy, should be closer, if not slightly over 20. On my f250 2wd automatic cruising @ - 2000 rpms (around 68mph) will get me that.

 

You guys are killing me. I get 11.9 in the city, hand calculated with a non lifted truck with michelin ltx ms2. I drive easy , ebps tube was cleaned , all synthetics.

 

16-19 here, depending on the drive, the traffic, or my mood. Your rig is very similar to mine... I have 3.73 and typically drive no faster than 65 MPH - but 75 MPH gets me 17.5 MPG on the flat with no wind. Florida is flat, so we can rule out mountains or altitude. A lot of stop and go with mostly stop? Short trips? A/C all the time?

 

Tugly,ac all the time, stop and go city driving. I drive it easy.Truck is in very good condition. I am the original owner. I get 14 on the highway. I would love to figure it out. It coast very well ,so I don't think there is any brake issues.

 

People here might already knew this. However, just I case someone don't know, you need to fill the tank to neck full of green liquid, not white foam. It does take forever to do that. However it's the only accurate way.

 

2000 2wd zf6 105k I've been keeping a running tab on my weekly mileage and my numbers are as follows


F250 mpg
17.9
21.9
18.6
19.7
19.6

I run a 150-1 mix of 2stroke oil and DON'T especially baby the truck in a mixture of what I call rural driving. All these figures include at least some pontoon boat towing.

 

Mine jumps all over the place looking at the overhead(which is fairly close to hand calculations) The worst mileage will be seen on a cold engine. If you live close to work, and don't get the oil nice and warm, the calibrations used are extremely thirsty. Once the oil warms up, they're much more economical.

When I lived in town a few months ago it was 3 miles to and from work, then a few miles to lunch and back everyday. Just enough to get the engine warm them shut it down. Mix in a few red lights and stop signs, and I was lucky to get 13.5.

No that I'm up the country with a 25 minute drive (15 hwy at 70 and 10 in town with few lights at 50) I can see more than that. 15.5-16. That still includes the cold runs to lunch everyday.

Now Monday I reset my overhead (right after the hutch mod this weekend) with the engine already warm and drove 70 miles, parked for 20 minutes, another 70 and short park, and another 30 back home (speeds were split between 55 and 70). I was looking at 18.7. Driving cold into work this morning I watched it drop to 17.5, then climb back to 17.7 after the engine warmed up.

That's why a lot here have such varying results with mileage. Some let their trucks warm up before leaving the house, and have a long slow (60 or below) commute. Some crank up and go and live 2 miles from work. The optimum seen is going to be about 21 on the best day. 17-18 and you're doing good. 15-16 is fair, and 14 and below is poor. (All based off if 4wd CC short bed with 3.73s.)

 

That A/C is doing you no favors - but 14 is a little low. How fast on the highway? Have you already visited the MPG thread? I don't keep tabs on where that link is (the one thing I never had a real problem with), maybe you can search for it or someone can post it. Confirmed odometer accuracy?

 

Under 2000 rpms on highway, I checked the mpg thread. I have not checked the odometer I will do that. My tire size has increased to 285.

 

Just another point of reference for comparison...

2WD, auto, synthetic oil, 2" front leveling kit, 285 MS2's, OEM exhaust, no chip, 6637 intake, I'm not a mild driver, but also not wild...

65 mph on fairly straight and slightly hilly county roads will land me at about 16.5 mpg doing 90 mile trips consecutively. Part of that 90 miles, though, does include about 20 miles of interstate where I run at about 78 mph, and another 5 miles of stop-n-go while getting out of my neighborhood and onto the interstate.

I know that I have a partially plugged EBPV tube or bad EBPV sensor, and suspect up pipe leaks as well, but the uppies are not bad if they are leaking (most likely do leak since they are original with nearly 240K miles on them).

 

I will forward this info to him. Thanks guys.

FYI, I get between 18-20 in my truck. 20 is a rare occurrence though.