I just increased my 80's MPG for free and you can too! (1 Viewer)

[zona]

A quantum decomposition of gas mileage requires and algorithm with a coefficient linear to my foot, because I'm going to put it in your arse if I hear anyone complain about gas mileage anymore.

Zona

 

[richardlillard1]

My favorite picture:

When griping about mileage, let's put something into perspective; what would another full-size, solid front axle off-road vehicle get? A K5 maybe around 7?

Build it how you want it, take it out often and you'll find it runs on smiles to the gallon.

Bet on it.

 

[Dragos80]

I guess I am a tree hugger. My 80 is a green car too, just like the one above my post. Same color.

 

[greentruck]

We've got, ahem, a greentruck here, too.

 

[musthave]

How many more MPG should I expect after a apply a Hybrid sticker on the rear window?

Your answer could also be in metric too, it doesn't matter that much because I got an app for that.

I put mine on and it just feels faster, almost stealth-like. MPG? Eh' what's that?

 

[Dragos80]

View attachment 1158043
We've got, ahem, a greentruck here, too.

That's it.
Can we get a tax break now? Or be able to use the carpool lane when driving solo?

 

[math]

That's it.
Can we get a tax break now? Or be able to use the carpool lane when driving solo?

No, the 80 doesn't go fast enough for that!

 

[BulletHead]

Hmm. I wonder if Prius drivers ever discuss/compete in "how to get the worst possible MPGs".

 

[Dragos80]

No, the 80 doesn't go fast enough for that!

I got it up to 90 and @scottryana well in excess of 100MPH

 

[math]

Hmm. I wonder if Prius drivers ever discuss/compete in "how to get the worst possible MPGs".

Yes, we do. We managed 16mpg in boiling hot Las Vegas traffic, stop and go with the tires at like 10PSI and the car loaded down with hundreds of lbs of gear. Ah, for the halcyon days when we thought 16mpg was bad...

I got it up to 90 and @scottryana well in excess of 100MPH

Falling off a cliff, maybe! I'm sure our 80's can manage 100mph, though. How long it takes to get there is probably another story. Well, we can cry about the 80's mileage when we hit 300,000 miles without any trouble or a rebuild, on whatever beautiful trail we're wheeling on. The 80 is what it is, and I'm thankful for that.

 

[Funner]

Agreed. I don't worry about or seek MPG either but double digits are nice.

Sounds like a politicians use of statistics, 2 is not considered "double digits" by most

 

[msapers]

Sounds like a politicians use of statistics, 2 is not considered "double digits" by most

Um...ok. but 9MPG is single digit mileage whereas 11MPG is double digit mileage.

 

[lcwizard]

Personally, I revel in the mileage I get with my cruisers... I'm determined to leave this world knowing there's no gas left for the spoiled
rotten kids of today to enjoy. I just don't want them having more fun than I did...in fact if ever I approach 10 mpg's I just attach this baby...

 

[Funner]

Um...ok. but 9MPG is single digit mileage whereas 11MPG is double digit mileage.

HAHA, i thought you were claiming double digit gains. reread your post and see that you just meant getting to double digits. Still sucks though

 

[95ToyCruiser]

That is highly unlikely figure unless you are driving slow, can be done. Most people will not believe me, but my best mpg of my 97 is 21.5 MPG, driving 50MPH from Telluride to Moab with 2" lift, 33" tire and front ARB bumper. And my bro was trailing behind me in a 96 with Yakima warrior rack and 1 slider on the rack, he got about 20mpg. the sweet spot for best MPG on this rig is around 50MPH, problem is not many has the patience to drive for hours with that speed. I had no choice due to truck and multiple vehicles up front, so achieve that MPG accidentally. But if I cruiser at 80 MPH, my MPG drop to approx. 10MPG!!!

Doesn't the torque converter lock up at ~55mph? Wouldn't you think that to be the optimal efficiency?

It would be nice to be able to change the lockup point to, say, 45 or so...it seems that would be a huge help to the MPG...

Can someone please make some sort of trans ecu piggie back that could give changing shift points and lockup?

 

[Whileemptyheadsdream]

That is highly unlikely figure unless you are driving slow, can be done. Most people will not believe me, but my best mpg of my 97 is 21.5 MPG, driving 50MPH from Telluride to Moab with 2" lift, 33" tire and front ARB bumper. And my bro was trailing behind me in a 96 with Yakima warrior rack and 1 slider on the rack, he got about 20mpg. the sweet spot for best MPG on this rig is around 50MPH, problem is not many has the patience to drive for hours with that speed. I had no choice due to truck and multiple vehicles up front, so achieve that MPG accidentally. But if I cruiser at 80 MPH, my MPG drop to approx. 10MPG!!!

I had my 95 running 55 and was getting 20 plus MPG with KM2 37 on it. I said I was getting 20 plus In a thread and people joked about It. I drive 2 prius cars a 2nd gen and new 3rd gen so I have a light touch . I know you can get really good mileage In these 80s with stock gears. I built ARB lockers ft. and rear and put Nitro 5.29 gears in new cases and my mileage sucks, I am tempted to switch back to 4.10 . I am building this rig as a hobby and hate to see the miles go up 12% more than It should be. If I was a young man I would just swap them out before I go to the dunes. I have really bad Arthritis so my hands don't work like most peoples. These mileage statments I believe though, you can do it..! ! Good Luck..!

 

[Whileemptyheadsdream]

A Prius is a great companion for the 80. Just saying.

That said, we get 15-18mpg depending on how we drive. No third-row seats, no rear seats at all, no interior, period. So it's lighter than a normal 80, probably. But the absolute most important factor regarding mileage is your right foot. The slower you safely go (to a point), the better. Drive at 55mph on the interstate and you can just about make it to 19mpg. We hit 20mpg once. You can also draft at a safe distance behind a slow-moving semi, though this may result in the engine warming up.

There have been many arguments regarding efficiency of the AC vs having the windows down, and for many smaller cars. It turns out that at highway speeds, the AC is more efficient than having the windows down, because at those speeds, aerodynamic drag is the predominant force affecting fuel efficiency. At slower speeds, it's better to have the windows down, since the aerodynamic drag is a function of v^2 (a function of velocity squared).

It is an open question as to whether any of this applies to a vehicle with a drag coefficient (Cd) as high as the 80's must be. The parasitic affects of windows down may only match those of the AC compressor at very high speeds. This is because C_d is probably not increased greatly by opening the windows.

So let's calculate the force on the 80 for fun.

Fd is the drag force of an object, and:

Fd = .5 * Cd * v^2 * ρ * A, where

Cd is the drag coefficient, which we don't know and I couldn't find. According to wikipedia, it's Cd=0.35–0.45. It's an 80, so let's not pretend it's not 0.45 or higher. So we'll take Cd = 0.45. ρ is the density of our fluid, which in this case, is air at 68 degrees Fahrenheit and at sea level. It's equal to 1.2 kilograms per cubic meter; v is our speed (suppose 60kph or 25 meters per second); and finally, A is the area of the front of the 80.

We went outside and took a (very) rough measurement of the 80's frontal area, which was 1.2192m tall * 1.9304m wide. This is 2.353 square meters. This does not include the correction for windshield rake, because a) it's not very steep, and b) it probably changes by a few degrees depending on conditions and whether you're stink-bugging it. This does not include tires or suspension or your 8-inch HIDs and roof rack and the deer you've got dangling from the ARB bumper.

Therefore, we have, at 90 kph, or 25 m/s:

Fd = .5 * 0.45 * (25)^2 * 1.2 * 2.353 is roughly equal to 397.069 Newtons. This is the force your truck must overcome at 90kph to keep moving forward.

Yep, it's a pig. Now pop those windows down and I'm guessing your Cd = 0.5.

So that becomes:

Fd = .5 * 0.45 * (25)^2 * 1.2 * 2.353 is roughly equal to 441.187 Newtons.

So at 90kph, the difference in drag is about 44.19 Newtons if the windows are open at 90kph. When does the AC compressor create a drag equivalent to 44.19 Newtons? Someone who knows those systems will need to chime in, because I don't know that. Bear in mind a lot of these numbers are made up, but it should help put everything into perspective.

Thats just AWESOME !!!!!!!!!!!!!!

 

[Whileemptyheadsdream]

Hmm. I wonder if Prius drivers ever discuss/compete in "how to get the worst possible MPGs".

I have not heard that discussed EVER...! lol !

 

[team420]

Wow... I'm amazed at the mpg ratings I see here. I know I live in th middle of no where, but I'm rolling on 34's. stock height, stock everything really, with 230k miles, and I honestly get better mileage outta my rig, than I ever did outta my 4runners, and it has more nut to boot. 18mpg, and seems (never really timed it, but did beat my buddy in his 4runner in a sand drag) to get up to speed hella quicker.

 

[jaymar]

I went from a consistent 10.7 avg in L.A. non-rush-hour traffic, up to 12-12.5 avg with one technique: employ Cruiser control at every opportunity, even between stoplights--but kill it on steep upgrades (where it wants to pump a flood of gas and drive RPMs through the roof) and downgrades (where I've been up to 123mpg before getting the 9999 on my ScanGuage). When you know you won't make a light, kill the Cc and drift. I only do 50 miles of freeway a week (20-23mpg on a straightaway, but too many mountains for that to stick), so that's not skewing my figures. And I almost never go out near rush-hour. No third row, big cargo box, 33x7.5s more or less, ARB up front.