Pure Highway MPG Test

[Andree]

This is for everyone. Stick shift. Automatic. Pop, Sport, Lounge, Turbo, Abarth, 500L, 500x, and any classic Fiats.

The EPA has their testing. The rest of us have our daily real world driving experiences. And we end up with all kinds of results for our mpg. My "city driving" isn't the same as your "city driving".

But there is a way we can compare, fairly equally. The pure highway mpg test will do it.

The instructions are simple.

Find a gas station near a freeway.

Fill up to the first click. Note your odometer reading, and/or set your trip odometer at zero.

Get on freeway, drive 50 miles. Steady speed.

Exit and reenter freeway, drive back 50 miles and return to the gas station.

Fill up to the first click AT THE SAME PUMP.

Use the odometer/trip odometer number and the gallons used to fill up to calculate your mpg.

I posted my results in the 500 Automatic (edit, my car is the regular 500 automatic Lounge trim) mileage thread, and here's a copy and paste:

Starting miles 2435
Ending miles 2522
Total miles driven 87 hand calc, 87.2 via EVIC

Second fill up used 1.930 gallons. That is how much was used to travel the 87 miles.

MPG: 45.97 hand calc - using 87 miles traveled
45.18 hand calc, 41.6 via EVIC using 87.2 miles traveled.

Time to travel: 1:30
Ave speed: 56 mph

http://www.fiat500usaforum.com/showthread.php?7295-500-Automatic-mileage&p=709075&viewfull=1#post709075

As with the real world variables, I did encounter a few stumbling blocks, when the traffic backed up, came to a standstill, because of the Highway Patrol doing traffic calming. And I got lost on various offramps and construction areas. This would have had the result of lowering my highway mpg. And my average speed, as I mostly drove 60-65 (speed limit 65).

I used cruise control the rest of the time, occasionally clicking down a few mph due to traffic, and then back up. Mostly steady driving.

You want a level freeway. Or one that has it's ups and downs, but isn't extreme uphill in one direction and downhill in the other. This test may not be useful for some areas that do have mega inclines or lots of twists.

This is PURE HIGHWAY.

The reason for this is to know what your vehicle is capable of, and what it IS getting ON THE HIGHWAY. Straight, unabashed, ho-hum highway.

It won't be mixed in with the trips to and from the freeway. Home, work, stopping for lunch, etc. You're eliminating all the non-highway gas sucking idling at stop lights (zero mpg).

This will tell you your real mpg while you are on highways in similar conditions. I now know what I am getting when I drive even a few miles on the freeway at the same speed, still should be getting that wonderful 45 mpg, over ten miles as I was getting over 80 miles.

And, if you noticed, my average mpg according to the trip odometer EVIC was several mpg LESS than what I actually got. You may find the same thing. The average is an average...it's not measuring the fuel as accurately as the gas pump does. That's why you use the gas pump gallons to calculate your mpg.

It took me awhile to get around to doing this myself, so I don't expect everyone to jump on the idea immediately. But it's there. I found the drive to be relaxing and pleasant, scenery was soothing.

Give it a whirl, and post your results. Starting/ending odometer, gallons used according to second fill up. Speed you were traveling helps too.

[Andree]

way to much work, I fill hers up when it starts to get low. Mileage meh not overly concerned.

Way to harsh my mellow!

[boostfreak]

way to much work, I fill hers up when it starts to get low. Mileage meh not overly concerned.

Then why are you in this thread?

I'll give it a shot

[Andree]

I'll give it a shot

YAY!!!

[opiateESP]

I'll try this out this weekend. Can't say I've ever even really looked at my mileage but i'm sure it'll be interesting!

[ophidia31]

While this works out in the short run and gives you an idea, I can easily flubb the numbers to get better or worse in that short amount of mileage. Can hypermile the thing (speed up quick, coast down, repeat) and probably get upwards of 40+. But thats not how I drive. Ill stick with my 34mpgs I get now.

[MemoryFoam]

I think 100 miles is too short a distance to overcome driving & fill-up variables.

http://www.fiat500usaforum.com/showthread.php?16065-Road-Trip&p=684935#post684935

[Tweak]

Then why are you in this thread?

I'll give it a shot

Reading his posts give me such a feeling of deja vous even when it is oh so tiny a request being made.

[Andree]

I think 100 miles is too short a distance to overcome driving & fill-up variables.

http://www.fiat500usaforum.com/showt...935#post684935

Hmm, I drove at 60-65 mph on cruise control. Can you try out 65? I think you lose mpg quite fast above that. I'm in an automatic regular 500 (Lounge trim), it has the six speeds. In the manual with five speeds, winding it out will probably cut into the mpg more than it does with the six speeds.

And let me ask you, if you could get 10 miles more per gallon by reducing your speed from 70 to 65 mph, WOULD you drive 65 mph?

I prefer driving slower, with a max of 60 or so. I like 55 mph, on the freeway. No, I don't get anywhere fast, but I don't have anywhere to go that requires me to get there fast. As long as I stay out of everyone's way, in light traffic, I don't think it's a problem for anyone else.

On this trip, after being whizzed by, by everyone, I'd click the cruise control up one mph, try that speed, and just click up or down as needed. It was only my second time using cruise control. I really like how I can choose my speed precisely, one mile per hour at a time.

[Andree]

While this works out in the short run and gives you an idea, I can easily flubb the numbers to get better or worse in that short amount of mileage. Can hypermile the thing (speed up quick, coast down, repeat) and probably get upwards of 40+. But thats not how I drive. Ill stick with my 34mpgs I get now.

I don't think you have to hyper mile. I didn't. I used straight cruise control. The car does all the work. It speeds up, it slows down, it keeps going at a constant speed.

And yes, a few traffic snarls, and you lose some mpg. Nothing you can do about that, unless you want to keep making mpg runs until you've achieved the PERFECT mpg run with no traffic, no slowdowns, no hangups.

I probably should have planned out the run to find a cloverleaf freeway intersection, so I didn't have to exit the freeway at all, or stop at traffic signals. I will try to do that the next time I make a run. Minimal slowing to max out the mpg.

[Andree]

By the way, nobody HAS to do this. It's not a competition to see who has the best, it's more for our own personal information to see what our cars are capable of.

I have posted the story in the other thread, where I had my Honda Fit tested. Had to do with the mpg being totally off, showing we were getting more than we were actually getting, and there was a service advisory and flash update made because of the test. Everyone was complaining, but nobody wanted to take their car in to address the problem. So I did it.

And the mechanic did the test that I did, the mpg test. The instructions came from the Honda corporate place. That allowed a comparison between what the car was showing as being the mpg, and what the actual mpg was. With the Honda, it showed everyone was getting 10 percent better gas mileage than they were actually getting, and people felt that was deceitful.

Now, if the average on the Fiat is underestimated, and people are only using the evic info from the trip odometer, they may be getting MORE mpg than they thought they were. I did. My trip odometer showed only 41.6. My hand calculations showed 45.18.

This is a way to compare your mpg against your trip odometer. Very valuable information, to me.

This is a way to compare your highway drive with others, without any special circumstances. Use the cruise control, try speeds between 60-65. Folks with manuals shouldn't have to be downshifting or upshifting, it will just be a nice steady speed on cruise control.

And now that I know how to use cruise control with some confidence, I'll be using it more often.

This is for YOU. For YOU to know what your car can do. It's a special circumstances kind of drive, that you normally wouldn't be making.

For me, it was a delight. Why? Because all my driving is low speed, no speed, stop and go, parking lot driving, idling, parking. And I get horrible gas mileage because of it. I have also only been using the trip odometer reading, which may be less than what I am actually getting, as I discovered on my highway test.

Now if someone asks me about my mpg I can proudly say it gets 45 mpg highway. Because it does.

And I'm expecting surprises for each of you, for the people that try this out. It's too hard to compare random city driving or random highway driving. This is trying to compare on equal grounds, on mostly flat highway, at a mostly controlled speed, without any special driving skills required.

It's a gift. For those that have less than ideal daily driving habits and roadways and routes, it's a gift to you to know that your car is capable of great mpg. And IS getting great mpg under the same circumstances.

[Andree]

Have at it but this test is anything but real world or long term accurate

No one is going to do it anyway, as I already wrecked the thread by explaining too much. And you didn't exactly help. I can wreck things on my own, thanks.

The only thing missing now is the appropriate clip from the movie "Clue" with Martin Mull saying "That's right".

[Fiat500USA]

I think it is a fun little test, and will try it when I get a chance. Don't let the noise bother you. Letting the cruise control do its thing takes you out of the loop somewhat, so you rely a little more on the car.

[snakebite4767]

No... it's not "Real World", but so what. It could be fun to see just how high it could go. Kinda like some of those High Mileage test done on the Salt Flats where they squeeze out 1,258,000 mpg! I live too far from a Highway to run out and do the test, but if I can fit it in the next time I have occasion to travel that far on a level road I might give it a try.... just for giggles. I did a real world test last weekend. It was over Hill and Dale..... actually some very BIG hills. MPG becomes more important the farther you live from town.... and the more you drive. I bought the Fiat to do my "Running Around" here at home rather than use my new Truck which I need to pull my 5th wheel. By not using the truck, I went from 13 mpg average with truck and no trailer, to 39 mpg average with the Fiat. I expect to put maybe 10,000 miles a year on the Fiat. That is a savings of around $2,000 a year in fuel alone! At the $12,000 that I paid for this Fiat, it will pay for itself pretty quickly.

Bottom line is this... unless you put on MANY miles.......... it just doesn't matter what your mpg are.

Snakebite

[JimmyTestarossa]

The test sounds interesting but I'm not sure I will be able to contribute. I have an app on my phone that I use to track fuel mileage. It is often in disagreement with EVIC.