20 Mpg

[Lanceorama]

I'm not a frequent poster, but I do lurk on the list getting info. I own a stock '97 with a mere 71k. I drove to Iowa last Thursday (3/1), and recorded 20.41 mpg.
I'm kind of a nut about recording my gas and mileage and have since I bought the rig at 38k (my wife thinks "it's cute" but we're newlyweds, and "cute" may be her way of saying that it is really kind of an overly anal waste of time).
This is by no means my normal mileage, and I attribute the boost to freshly inflated tires (like to do that before any long highway trips) , and an absolute killer 40mph tailwind (anyone on the list in Missouri, Iowa or north of there can testify to last weekends windy & wintery weather).
My normal mileage is about 12-14 in town (much less if I use the remote starter in the winter) and 15-17 on the highway. Although I did average 17.5 on the way back Sunday.

Anyway, back to lurking. Best to all of you.
Lance

 

[cpg]

My normal is 11.5 to 13.5 I did get almost 17 going mostly down hill.

 

[Buckru]

As long as I can go down hill both ways, my mileage rocks. Other than that 14mpg.

Buck Buchanan

 

[e9999]

well, if it was really 40 mph tailwind, you had the aerodynamic drag of 25mph with the engine perhaps running in its most efficient band. Possible I guess...

 

[NaterGator]

I average 10-11 mpg in the city and 11-12 on the highway. I did just throw a P0420 so I probably need new oxygen sensors, but I don't expect that to boost my mileage much...

 

[wfd175]

Last month, I had an extreme headwind from StL to Chicago and and tailwind back, on the way there I was down to 180 miles per tank, and the wind was forcing shifts out of overdrive when going over the overpasses. On the way back I got almost 290 miles out a tank.

My regular average is 220 per tank. All in town driving. With a refill of 20 gallons (when the light comes on) I throw o2 codes once in a while. I may be due for sensors.

 

[cruiserdan]

It is possible to crack 20. I know of a couple who have done it. Usually it is a stocker, in top tune with a light load and running ~55-60 mph.

DO NOT OPEN THAT HOOD AND TOUCH ANYTHING!

 

[archie]

Curious, are you running stock tire size? What PSI did you inflate?Thanks!

 

[toylndcrusr]

We just gave our '97 to my wife's brother in Altanta, and it is stock with stock tires and gets about 18mpg. That's with about 125K on the odometer.

 

[hadji_85]

oh how i envy you

 

[matt60/80]

A while back I tried to see what kind of milage I could get out of the 80 on the highway. I set the cruiser to 65mph and managed to do 18mpg. Normally I hover around 14-15 regardless.

 

[flem0061]

Just ran a tank with Redline Total Fuel System Cleaner and got 10.9 mpg out of it with a mix of city and hwy. Do additives reduce mileage when they're in the tank?

 

[p8nt]

this summer I got about 14.5 on average, however since the winter hit, Im getting about 12 on average. What makes "winter grade" fuel and why the worse mileage?

 

[Pete483]

I drive between Atlanta and Clarksville, TN, about 316 miles a couple times a month. If I'm in a hurry I average about 75 mph and can barely make it on one tank (fill up about 24 gallons, though I usually fill up well before that), somewhere in the 13ish range. If I'm not in a hurry and drive 60-65, I can make it one tank and drive work a couple times ~380 mi and put in 23 gallons for around 16-17 mpg.

I also have a 97, though mine is with 170k, though it was rebuilt after 125k after is sh!t itself. I have 285 mud terrains that I fill to 50psi for the highway as well, so I feel my mileage is pretty good.

Certainly helps to slow down that little bit, and I could certainly see a constant 40mph tailwind pushing you to 20mpg.

 

[cam75w/ls1]

240 per tank period. Never goes on the highway but when it does I'll check and see what it gets.

 

[Tools R Us]

On this tank the light came on at 225 miles, the first tank with the 37" tires on, mileage uncorrected and stock gears.

 

[Brian894X4]

Does the mileage always go down with 33s and stock gears? The reason I ask is I wonder if the "higher gearing" might actually improve mileage on at least the highway.

Of course, there's so many factors that have to be considered, such as the all the extra weight that usually gets added to a rig with 33s, and whether or not the mileage was correctly compensated for the difference in gearing.

 

[taccruiser97]

Mine gets generally in the 14s but coming down out of the mountains in Colorado coming back from Crested Butte last August on 50 hwy, I did appoach the holy grail of gas mileage for 80s, 20 mpg, no AC and just cruising at about 70. I think high teens to 20 mpg can be achieved under right set of rare circumstances.

Let's not talk about my MPG going up into the mountains though. I did pay $3.45 a gallon for gas in Crested Butte. Luckily for me I was just topping off my tank with 4-5 gallons before we went over Tin Cup to St. Elmo.

 

[cruiserdan]

this summer I got about 14.5 on average, however since the winter hit, Im getting about 12 on average. What makes "winter grade" fuel and why the worse mileage?

"Winter fuel" is usually oxygenated by some method (often cut with ethanol) and the resulting blend does not have as much stored energy.

 

[p8nt]

"Winter fuel" is usually oxygenated by some method (often cut with ethanol) and the resulting blend does not have as much stored energy.

Thank you sir, much appreciated! What determines the time frame the "winter grade" is in use? Do they go by the calender or current weather? Are all grades (i.e. premium) of fuel affected? What is the logic behind oxygenating?