yeah it definetly worth it! lol and yeah we do

 

god i wish i could get more then 12-14 out of my pickup lol just last night i filled up and got 12.56...

 

Something is wrong. I got 16mpg towing our boat with gear, 14mpg in the city when I tow a load of 6K lbs. When i am unloaded I get 21/18. But thats when I "baby" it. When I am unloaded and in a hurry i get 16mpg in the city.

 

I have an 01 4.2 and i get maybe 17 to the gallon when im trying

I had some problems when i had a coil go out on my truck i waqs only getting about 13 to 14 then

 

1st, with the mileage. you have a 98, ford didnt update teh computers untill 2000 at least with the 4.6L. my uncle heard that straight from ford. his 97 4.6L ext cab 4x4 was only getting 12mpg with about 110k miles. they told him they updated the stuff in 2000 so 97-99 had poor gas mileage, so that might be one.
2nd, 3.55 is worst for mileage. if you want better mileage go with a 3.31 or 3.08(both are stock configurations) 3.08 is best for highway. i had an 04 heritage (03 style)reg cab longbed 2wd manual with 3.08 rear end. stock average mpg was consistant 18.9mpg, with K&N drop in filter i got consistant 19.9mpg and with K&N 77 series intake i got 22.5mpg consistantly. i traded my 04 in for an 08 but took off the intake and put it on my 08. i dont know mpg stock but with intake i am getting around 20mph average with reg cab shortbed 2wd 5speed with 3.55 rear. 3.55 is standard on the towing package, 3.08 is for highway. if you want pulling power but better mileage, go with a 3.31 rear. if you dont haul much, go with a 3.08 unless you have extended cab or 4x4, then go with a 3.31. of course you can get whatever you want but those are the stock ratios i know of so they would be easier to find

also forgot to mention. i drive a standard which is a 5speed compared to the auto's 4 speed. either way 3.08 is the best for mileage but my info was for manuals. if you have an auto the tranny's gearing is different thna the manual so my 3.55 rear ended truck i have to shift into 3rd at 50-55mph whereas anauto i have heard shifts to 3rd around 70

 

shift to third at 50-55... holly ****... my pickup is screaming and the battery light flashes on and off really really fast when i get about 40 in second... i would blow the thing up it if went to 55 in 2nd! i go to 60 in 3rd and it is screamin then!

 

I have shifted my 5 speed (3.55 gears, 255/70/16 tires) at 30, 55, and 80. It hits the speed limiter before 4th is wound out. It has never hit the rev limiter. Those shift points are approximately 5200 rpm.

You sure you don't have 4.56's or something? Have you ever calibrated your speedometer and odometer against the highway mileposts? Do you have or can you borrow a GPS?

 

for GLC... how fast is your speed limiter?

for 4.2l guy, thats insanely slow for those gears. my 3.08 in my 04 heritage was 1st to 40mph at limiter(5400), 2nd to 65 at 5200, 3rd to 90 at 5000, 4th i had up to 108, dont remember rpms but i know at 100mph it was 3600rpms. my 08 with 3.55LS is the same as GLC's, 4th at 100mph is 4000rpms which is also the speed limiter(100mph). you gotta have 4.10s in it or something. plus your tranny might be geared a little closer than ours, could have been changed before you got it if the person only used it for pulling heavy stuff on slow roads where he would only need to go like 35mph or something. also, 4.2L guy, is yours 4x4?

 

lol or he can just drive like 90 and get pulled over, then ask the cop..."how fast was i going officer?" lol

 

My speed limiter kicks in at 96 on the speedo which is 94 on the GPS.

The rev limiter is 5400? I've been wondering what it was and don't really want to find out the hard way - at 5200 it's making enough racket! I don't have a tach - I used the diag mode on the odometer once to record RPM's and used math to calculate it out.

Actually, there is no reason to push a stock 4.2 past 5 grand - that's where the power really starts dropping off and it sounds like ***. My only mods are an Amsoil air filter and a cheap low restriction muffler which sounds like rice at high rpm's.

 

my 04's was 5400, my 08 i dont know but i do know the manuals have a lower rev limiter since autos shift on their own. and my 04's shift points i gave were the ones that made my turck move the quickest. too high in 2nd like you said power dropped off at 5000 or so but first seemed to be better to shift above 5000. and my 04 sounded great at all rpms. my 08 starts sounding weird above 4500. also i noticed with my 04 that with a cold air intake the trucks rev limiter raises. i know it doesnt sound right but before i put it on i just put it in 1st and kept going until the truck stopped gaining rpms and i dont remember rpms but the speed was 35mph then it kicked down. with the intake i could hit 40mph in 1st. did same thing in 2nd gear too.

 

I finally checked the mileage on my stock 07 XL, standard cab, 8' bed, V6, auto, 22000 miles, stock wheels and tires. The past week, mixed driving...approx 70 percent highway, but about 100 miles of that with a very non aerodynamic 1000 lb load in my bed, I got 20.6 mpg on 87 octane regular. I normally travel between 65-75 mph on the highway. I was happy with the results.

 

i just figured the approximate mileage for mine from full till 3/4. got 155 miles on about 6.5 gallons which is 23.85mpg. has 9300 miles and only a cold air intake. also found out the 4.2 is very efficient with the 3.55s at 25 to 35 mph which is 3rd and fourth gears. i went cuising for about 5 miles at those speeds and i am almost positive that is why mine jumped from just over 21 to almost 24mpg

 

well my brother owned the pickup before me and said he has had it to 85 in 3rd. i will never do that much. it sounds like it is screamin like a mo fo at 60 in 3rd. might just be the exhaust he put on there tho. it sounded like **** but was loud. i never went over 25 in 2nd when i had the exhasut on there casue it was so damn loud. i put the 2.5 inch exhaust on it and at 25 in 2nd is where the exhasut sounds like a v8... so i know there is at least 2000 rpms left. but i always shift right when the good sound starts to fade away. so im sure my pickup never gets over 3500 to 4000 rpm unless im racing someone which is very rare. i think i have raced 5 people in the 6 years i have drivin it. (3 years owned) lol

i dont know tho. im gunna go look at the window sticker to see if it says just exactly what gears it has... im pre sure it has 3.55 tho. all i know is in 4th at 65 to 70 is where is sounds the best in that gear. so that would mean it is at about the same rpm in that gear as it is at 25-30 in 2nd

here is when it sounds the best in each gear.
1st 13-16
2nd 25-28
3rd 37-40
4th sounds good anywhere from 55-70
5th cant really hear a good sound in this gear. well kinda its at about 75-80... so yeah

 

yup just looked it has 3.55LS rear end. so for anyone with a tach and stock tires with 3.55 rear end. what are you running at 25to 28 in second and what are you running at 37-40 in 3rd?