[keith_1963]

Ok, Ive read a lot here about who gets what for MPG etc.. As far as I can tell it's disputable that if you want economy, keep it under 2000 rpm. I'm stock, except the K&N intake, at 2000 rpm I'm just making about 67 mph. Now in Connecticut, doing 68 on the highway is just not acceptable. Plus, I'd really rather average closer to 75 witht he cruise on.

My question is, does anyone suggest the mod to do to get to 75 and still be under 2000 rpm, or is it impossible?

 

[Believer45]

You can regear (I can get as numerically low as 3.08 for mine) or add an overdrive like GEARVENDORS or US GEAR, you will need to contact them to see if they can fit an Excursion.

It is possible to run 55-60 on the interstate, I do it often. Just keep to the right and watch your mirrors, if there is an issue developing behind you either pick it up for a bit or pull off an exit to let folks by. Many trucks are governed at 65 or recently even as low as 62 mph, depending on the company, and there are not accidents, fires, end of the world or anything where these trucks are. You just become one of them, as far as traffic is concerned.

RPM is not the only factor in speed. Wind resistance increases at the square of speed increase so if you double the speed you increase wind resistance by 4 times. My truck gets 17.5 or so at 75 mph, 19 or so at 65 mph and 21 or so at 55 mph, before switching to synthetic engine oil. First tank on synthetic oil I got 24.58 as reported HERE. I took my cousin's 2005 Chevy crew cab half ton to Washington DC from Cincinnati, OH, a few months back while mine was down and found the following:

Cruise 55 or 60 and get 24.5
Cruise 65 and get 21-21.5
Cruise 75 and get 18

Speed does make a difference. You have to develop patience to take advantage of that fact.

Dave / Believer45

 

[chuckster57]

Speed does make a difference. You have to develop patience to take advantage of that fact.

Dave / Believer45

Aint that the truth..But it's hard to do when everyone else is doing 75+. I am learning how to go at my own pace and not pay attention to all the other aviariacs (sp) Last year it was easy with $5.25/gal fuel though

 

[Believer45]

Actually, set the cruise, pop in a favorite music CD and go for it.

MY TAILGATE LETTERING usually helps keep folks off my bumper. I was originally going to put I BRAKE FOR TAILGATERS but that seemed a bit road rage if you know what I mean. I am still thinking about adding I BRAKE FOR NO APPARENT REASON below what is there.

 

[chuckster57]

We will be doing a 7000 mi. road trip starting in July with the 5er. LOTS of CD's and cruise control for sure. I will post our mileage as we go

 

[coronadojeff]

how are you getting 17mpg? i ust calc'ed out my last tank and was getting 11, thats not going over 65mph. mostly driving on the hghway. is there any tricks to getting better mpg out of a 6.0

 

[Believer45]

Slow down (sounds like you have done this to a point), drive like you have a full aquarium with no cover sitting on carpet that cost you $25,000 to install in your bed. Acceleration uses fuel, less acceleration uses less fuel. As a driving philosophy, brakes are your enemy. Any time you use your brakes, you are spending money on brake linings to get rid of speed that you spent money on fuel to get up to. Very little acceleration (I get outpulled by semis sometimes) and, as stated several times in this thread, slow down.

If you do a google search on hypermiling you will find a lot of information on things to do to save fuel. Some of the things the really hardcore folks do are not safe, in my opinion (shutting the vehicle down any time you can and coasting - you lose power steering assist and, after an application or two, power brake assist) but the theories are valid.

 

[TXANGLER]

just returned from a 500 mile trip. cruise on 68 with AC on. my best mileage ever at 20.75 hand calc'd and gps accurate. I usually travel 75-80 and get 17.5-18mpg

 

[keith_1963]

Im not sure what you can get from a 6.0 but with my 7.3 I pretty regularly get an hand calculated average of about 17, mostly highway around 70 and some around town. I never stomp on it, unless I really need to, seeing black smoke out of the tailpipe = fuel $$$. I also hate to brake, lose all that momentum you paid to get.

 

[Bruce1954]

Steve

You must have that white beast broken in and all softened up to get that many mile per gallon!.

I figure I am getting closer to peak MPG with only 108k on the 05.
Still want to try the gear vendors some day but 3k is hard to come by just to play.

Bruce

 

[Believer45]

Bruce, if you are referring to me, I have 278,000 miles give or take. The only engine modifications are an open element air filter and a switched 10k mod that I have not turned on in 4 years plus a LUK single mass flywheel conversion. I still have the original injectors and complete original exhaust.

I am purposeful about driving for mileage AND safety. When I drive Lovely Wife's Mazda MPV Minivan I get 21-22 mpg, she gets 17.5 or so.

Dave / Believer45

 

[TXANGLER]

hey bruce long time no talk. I have only 160K since closing my business and $5 diesel last yr. That is the first time since 01 I had enough self control and patience to drive that speed for any distance. I am still shocked at the MPG however my dad bought an 00 2wd and is averaging over 20mpg hwy. he probably hasnt hit his age on the speedo (69) since he bought it.

 

[keith_1963]

Just back from 600 mile trip, kept the cruise set at just under 2000 RPM, between 65 and 67 MPH, did the math and got 19.1 MPG.

 

[Beast]

Just a note. I have regeared mytruck and I would not assume you will gain any mpgs by regearing. I did not gain any mpgs. It does drive better with the 4.10s for what I need but do not assume that the key is 2000 rpms. I am sure its a combination of things but I would bet the wind drag is much more critical. I would bet FORD would have put 3.55 gears in the X if it would gain mpgs at 70mph. Just an opinion from someone who has done this.

 

[SIC-E]

on my fifth diesel and no telling why one does well and others dont. my 2004 E450 with 4.10s gets 10 mpg at best with 9500 miles on it. E350 that i just bought with 118k miles got 21 mpg driving 70-80 from MA to VA (saw what ya meant about conn.). ticks me off that the 2004 wont get near there but certain that even gears arent all the prob. love my $4550 E350!

 

[coronadojeff]

i forgot to add that my x is lifted 8" and on 37's, whats the equation for oversized tires? iso with the oversized tires then my speedo is off, and so is my odo, so i guess my whole calc is off.

 

[TXANGLER]

the max tire size the pcm can adjust to is 602 revs per mile or roughly a 35" tire. all u can do with 37's is go to a speedo shop with your revs per mile of your specfic tire and have them calibrate your speedo. then u need to gps it for accuracy. I would bet your mpg with the lift and tires to be 12-14mpg hwy on a good day.

 

[popups4rent]

With 35's and 4.10 gear I get 16 at 75 and it improves as I slow down. When diesel was expensive it was parked on long trips so I do not know what I could have gotten up to. The rental Camry got 32. In town I am getting 13. Before mods I could get the truck up to 18 on the highway.

All hand calced. I do not think this particular 6.0 motor was one of the economy ones that was produced.

Driving like an sterotypical sunday driver I only eeked out 1.2 more MPG and I figured the boredom to not be worth it.

 

[bigblueskies98]

how are you getting 17mpg? i ust calc'ed out my last tank and was getting 11, thats not going over 65mph. mostly driving on the hghway. is there any tricks to getting better mpg out of a 6.0

GET a 7.3! LOL j/k though i do get between 22 and 24 mpg consistantly with mine!