I really hate to bring up another mileage topic, as I have been using the search engine for a couple hours now and there are MANY of these.....but I have a problem and would like to hear yalls opinions.

Truck is a 01 SuperCrew 2WD with 5.4 116K on the odometer. Mods are 6" lift, and 315 (35") tires. Drop in K&N As well as a custom tuned XCal2 from Mike Troyer.

Fuel Economy is just the opposite, there is NONE, I am talking 10-12MPG, I do not drive retarded, most trips are 15+ miles in the highway, 65-70mph, not alot of city driving either.

Speedo is accurate so the odometer should be as well, and I am checking milage using the miles I drive off a full tank then gallons put in upon fillup, so this should be the most accurate way of checking. I have been keeping tabs on this for the last 10K or so miles a few months, and its been the same from last summer till current.

What should I do next? I am not looking to get a high dollar exhaust, intake, etc. I am not real concerned about those things, I KNOW that adding them will increase both perfomance as well as economy, but price vs increase in mileage just dose not add up to me. As even the XCal was not bought for performance so much as it was bought to correct the speedo, shift points etc after the tire upgrade.

Thanks for any help you all can offer.

 

You have 6 inch lift, 35 inch tires, in a full size truck, with the 5.4L, and you're running stock gears. and you are complaining about fuel mileage?

10mpg sounds better than what you should have in the first place.

what was it before?

 

It's not how much mpg's my truck gets cause it stay about the same city to city, highway to highway.

But if the price of gas would stay constant that would be a different story Cheaper gas means more miles per 50 bucks

 

Yeah I am complaing, sorry, and not to bust your bubble, but it should get better than this.

We have a similiar F150 2002, 6" lift 35's, with 85K miles and it gets 13+ in town, and 15+ on the highway.

I understand "full size truck" I am not a newb, nor a kid, and I know its not going to get 35mpg...but IF I am missing something here and I can get it up to 13-15mpg, I would be very pleased.....seems as though it should get this.

Stock I got 17mpg but it was stock 50K miles ago...after the lift and tires the MPG did not just drop all of a sudden, but over time it has gone bad....truck runs good, drives great, but the MPG sucks.

 

He may not have stock gears though, if you get 4.56 gears instead of the stock ones it will put your RPM's and power ban back to around stock level and should improve yourr mileage. I think nthat is what stopper was trying to say.

 

Is this the same Pahrump from various ATV sites?

 

Indeed it is....who is this?

 

It could be that your fuel filter or O2 sensor or PVC valve or air filter need changing. Especially since you say it's happened slowly over time, I'd take a look at those first. Also your MAF sensor may need cleaning.

 

I visit Yfztech occasionally, and my screen name is "wastecase".

 

I clean the K&N every 5K miles, but the fuel filter I will replace, and I read a good bit about the O2 sensors not really needing replaced unless they failed but I too thought it might be time to change out the 2 upstream sensors.


Can anyone give me their cruising RPM's at say 60-70-75MPH?


Thanks

Scott

 

My cruising rpm on a 2001 2wd 4.6l stock is around 1500 at 65-70 mph. Once I go beyond 70 it will approach the 2k area. I seldom go faster than that.

 

The oil in the K&N can foul the MAF sensor - try getting it cleaned.

 

I cleaned the MAF with some Letra Clean stuff, parts cleaner, and I swear the truck runs smoother, and accelerates better......


I just filled up witl gas so I will know in a few days if the milage is any better.

 

Hi,
Your rear O2's only need replacing if they fail. Your front O2's are more of a maintenance issue. I breifly skimmed this post down. If your vehicle has 50k. or more the O2's are starting to get toasted. Its not that they are not sensing proporly, its that they are Heated O2's and they do not get as hot when old. Not getting as hot, yeilds a leaner reading , yeilding a richer mix.
This was explained to me, I changed mine, It made a difference.

 

Well the o2's have 115K on them, I think maybe changing out the front ones will be a good thing.