Woo Hoo 19.7 MPG! (1 Viewer)

[ranma21]

You guys wouldn't believe this. The best mpg I got out of my FZJ is 21 mpg cruising at 45-50 mph with a loaded truck with no roofrack. If I cruise at 80mph, the best I will get is 12mpg. Such a big difference.

 

[rtarh2o]

Sort of makes you wonder why the government doesn't lower the speed limit back to 55 mph, just think how much we would save as a nation if every vehicle increased their mileage by that much. The newer cars are much more efficient but even my 2000 Volvo mileage drops considerably when I get above 70. Of course I guess our current government might have already figured out the implications of the 55 mph speed limit and that why it hasn't been changed!
Rusty

 

[C6H12O6]

Yeah, but you get there faster, so you are driving for less time, right? It would be interesting math for somebody to do a really scientific investigation of this idea of the ideal speed for an 80. The cruiser control question is a tough one, too.

Anybody volunteer?

 

[TX Cruiser]

Sort of makes you wonder why the government doesn't lower the speed limit back to 55 mph, just think how much we would save as a nation if every vehicle increased their mileage by that much. Rusty

I'd be SOL in my DD if that were the case. The mileage goes up as speeds reach 80. I have one of those nifty gauges, which appears to be fairly accurate.

I have a question, and some of you seem to be gurus at gas mileage calculations, so I have to ask. If my Cruiser is bone dry, not running, empty and I put 6.6 gallons in, then drove 111 miles to empty again, can I claim to get an average of 16.8mpg for my 3FE, or is that not an accurate reading?

 

[miked]

I've run into that same problem before. Since I knew I would be running this test, I made sure the gas was all the way up to the restrictor door in the fuel neck on both fill-ups.

I've done tests where I simply use the same pump twice hoping that the shut off is the same. I suspect that the gurgling/bubbling sounds mean that liquid and air are mixing OR that there are air pockets there's a trickle down and throwing off the observed level. Question.. how long did you let it sit after seeing that it was all the way up to the door? !!

I noticed that the US 101 between Camarillo and Woodland Hills, as well as the I-10 between Palm Springs and Chiriaco Summit are places where you can easily lose 20 MPH in seconds if you don't pay attention. And then the guy with the Cayenne behind you goes nuts. For that, I wish I had a manual trans.

For that, I wish I had a brick to toss out the sun roof. They bounce once .. windshield height.

 

[SOCALFJ]

The whole trip was about 224 miles (GPS miles, not odo).

Hey! I get 224 miles between fillups! Oh wait i have two 24 tanks!

 

[kup99]

I got 425 miles out of my last tank....... :whoops:.. I have a 38Gal tank

 

[IdahoDoug]

A single test would indeed prove unreliable, but I don't doubt that your fuel fill or miles were off. It is certainly possible to get one good fuel economy run but just a hair shy of 20mpg seems too high to me.

For instance, if you got 1.5gallons more into the truck your MPG would be 17.5 which is to me about as high as someone could achieve without holding to a 65mph speed in an 80.

Another thought. It's 192 miles round trip on Mapquest. Could you have forgotten to initialize your GPS at the gas station in Mesa? That miles on 11.37 gallons comes out to 16.89MPG which is about exactly what I'd expect for a well tuned 80 on road tires.

Anyhow, good economy run, but a pattern of this MPG would show what you're really getting vs a single run and uncalibrated fill.

DougM

 

[turbocruiser]

Measurements like that are highly unreliable. Depending on given condition, pump cut off valve sensitivity, vehicle load you can easily be of by 1 or 2 or even more gallons at fill up. I've experienced that particularly while towing trailer (with some other vehicle I have), pumps would cut off after putting 18 gallons in 24 gal tank while I know for sure I'm bone dry and even the gauge gauge shows 3/4 fill. Yet pup refuses to put in any more I less I point my truck downhill.

I would say any measurements taken with less then 2 or more full tanks are worthless unless you use some other container to assure of exact volume of gas. Like a jerry can or something.

It's really a wishful thinking that you can get 20 mpg on 5000lb brick shaped truck unless you run diesel.

Pretty pessimistic thinking there bud! I regularly get over 20 mpg highway whilst cruising at around 75mph (my rig is 5500 lbs as measured at truck stop scale, btw.) As you properly point out, one fill up isn't going to give you enough data to satisfy but if you go from FULL tank to FULL tank time after time after time and record it you are going to get a reasonably accurate rating over time assuming same driving style, same driving conditions and same driving demands, etc. It sounds like the particular pumps you are using are out of whack - I wouldn't use them until they are consistent. Or it sounds like this other vehicle has a venting problem of some sort where when it is loaded from a full trailer you are getting a good "vapor lock" which is shutting off the otherwise well working pump. I'm arguing that there is no way that there will be anything close to a gallon of difference let alone two gallons of difference between fill ups assuming that you're taking the gas up to the top of the tube; you might have a few cc's of difference but no way it would be a gallon of difference. I'm also arguing that it is indeed possible to consistently meet 20 mpg at relatively higher highway speeds. And I'm arguing that to a reasonable extent it is realistic to record mpg's using a combination of the gas pump and the vehicle odometer.

 

[Brian Macgyver]

Not to rain on any parades, but Phoenix to the Tucson area is all flat. Great mileage is not hard there. I once got my old 4cyl Montero to run 80 mph on that run!
From Prescott down to Phx, I use less than 1/4 tank of gas, but coming back I use a lot more. My last trip was a quicky, 2 hours in the city to visit a kid in the hospital. I left home with a full tank. Arrived with over 3/4 tank. Made one other stop and arrived home with 3/8 tank.
Real mileage is an average of flat, uphill and down. But it really feels good to beat the odds once in a while!

 

[gotmud]

Another thought. It's 192 miles round trip on Mapquest. Could you have forgotten to initialize your GPS at the gas station in Mesa? That miles on 11.37 gallons comes out to 16.89MPG which is about exactly what I'd expect for a well tuned 80 on road tires.

Did you type in my exact starting address or just "Mesa AZ" and "Marana, AZ"? I am several miles from the city center. And yes, I did reset my GPS at the beginning of the trip.

I realize that many of you are "doubting Thomases". I'm not saying that your rigs will get 20mpg, only that mine got close which was a big surprise.

I think the biggest factors here are an empty vehicle, properly inflated tires, and a consistent conservative speed.

I make this run nearly every weekend. I will try again in two weeks.

BTW, if my calculating method is off, how does everyone else determine their MPG?

 

[RescueU]

Not to hijack the thread, but what Mac/PC gas mileage calculation programs are being used out there? I've got a shoebox full of gas receipts and want to drop it all into an app to help record and track the MPG.

Thanks.

Sean

 

[Firedog]

Not to hijack the thread, but what Mac/PC gas mileage calculation programs are being used out there? I've got a shoebox full of gas receipts and want to drop it all into an app to help record and track the MPG.

Thanks.

Sean

I don't use one for the 80 (it uses so much gas I wouldn't have time to get on MUD.... I would always be entering mileage!) I do use an Excel spreadsheet to keep track of my mileage in my Chevy Duramax. I just use date. amount of fuel purchased, price of fuel (total), and number of miles registering on the odometer. I get a return of number of miles driven (both registering on the truck AND actual - I have oversized tires) actual mileage (adjusted for the tires), cost per mile, average mpg. average cost per mile and price per gallon.

 

[sundaypunch]

Another thought. It's 192 miles round trip on Mapquest.....

I have found Mapquest to consistently give me inaccurately low mileage estimates. I don't know if they calculate it in a straight line but my miles are always noticably more than what Mapquest says.