Fuel Economy

[Fiat500USA]

My trip computer and manually calculated MPGs are normally (and surprisingly) pretty close. Generally a few tenths to half a gallon off. I find if I did a lot of idling, like when working on my car, or during winter when I just run the car a few times to keep things lubed up, there is a greater disparity.

To get accurate manual calculations, I use the same gas pump, and generally get gas the same time of day. Pump to pump variations and temperature can affect how much gas goes into your tank.

Below is my average over 162 fill ups. I do about a 17 mile, semi- rural commute with about 10-12 stop signs/lights. I live on a pretty steep mountain road, and during my drive to work skirt a city. On the way back, I do about 3 miles at a steady 55 mph.



The ecoDrive program I had when I had my 500 Sport helped me fine tune my driving. It told me when to shift, which made a big difference for me. Generally, on a non-turbo 500, shifting just under 2,000 rpms yields best results. The advantage of MultiAir is it boosts low-speed, part throttle torque, so it allows you to shift at lower RPMS.

On my Abarth, I find shifting a little bit higher rpm or around 2-2100 rpm helped me get better gas mileage. That may be because I live in a hilly location and turbo boost comes into play with load. I drive to be smooth, use the cruise control a lot and try to stay off of boost for the most part. That helps me balance my habit of squealing the tires occasionally and trying to get a pop out of my exhaust. Whenever I get gas, I always tell myself that "this is tank I'm not going to screw around on". Never happens with this car.

Tire pressure also makes a big difference for gas mileage and I generally run 4 psi higher front and back.

[doverosx]

What do actual get, tank to tank. I only getting around 34 mpg. Highway and city combined. Using 91 octane, over the last 11 years.
My round trip was to work and back everyday. When I first got the car, I was using the Fiat Eco feature USB. That came with my car. I would
Try and modulate, my drive habits. It was fun the first couple months. Got old fast.



Every FIAT 500 equipped with Blue&Me or connect to 5.0
technology has access to eco drive, a free downloadable
software application that enables small business owners to
monitor employee driving habits, cut fuel costs by up to 16
percent, and reduce CO emissions.


Here's how eco drive works:
1 Download the eco drive app on your computer.
2 Create a profile, and enter your vehicle's information.
3 Plug any USB stick or compatible smartphone into your FIAT 500.
4 As you set off on your journey, information on the way you drive will be saved to the USB.
5 Plug the USB back into your computer to view trip data including total distance traveled, average fuel
consumption, and total CO2 emitted.
6 eco drive grades your driving technique on a 100-point scale, called eco:index.
7 Pinpoint areas of improvement, set goals, and track your progress over time.

The interactive app analyzes driving behavior and advises on improvement, focusing on the following four key areas:
• Acceleration
• Gear changes
• Average speed
• Deceleration

I recall trying to get this program to work and not having success. I think it was because it doesn't support the Abarth.

[map]

Interestingly, I don't find the displayed average mileage to be significantly in error. In your example that's an 11% error, which is huge. I reset it at the pump when I fill up every time. The system knows the amount of fuel injected since reset to a very high accuracy (the fuel pressure is regulated and the injectors flow a fixed rate). The biggest variable is tire diameter, but that is a fixed gain error that can be determined and corrected for - and I seriously doubt you're tires are 11% larger in diameter than stock.

I suspect there are far more variables in measuring a single tank via the pump readings - the pump shut off is not precise at all. This method is only accurate on a long term average over many fill ups.

You are correct. Actually, the tires are stock and (in reality) the odo is reading 1.4% further than I actually travel... but that's using a phone ap that say its 98% accurate so I use the odo when calculating.

Yep, I reset the trip computer with every fill. The previous tank started out at 16 MPG but jumped to 44, then slowly dropped and hovered between 38.5 and 39.8 for the last 100 miles. It's usually only off 2 or 3 MPG, always higher than measured MPG. 35.8 is reasonable, as I've averaged 34.9 for the last 12 months, logging each tank/mileage in Fuelly. Filling the tank at the slowest setting is helping level my measured MPG.

I usually use Chris' tactics, same pump, minimum of 40/30 tires, shift up at 2200, and avoid idling. What kills my mileage is all the short trips and 77% is around the city. I'm getting pretty good at timing the (usually wide spaced) red lights. And for some weird reason, the car prefers Shell, the most expensive station in my area.

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[smark]

I recall trying to get this program to work and not having success. I think it was because it doesn't support the Abarth.

I got this 1 gig flash stick from Fiat. You inserted into the USB slot, in the glove box. You had push the the speak button on the steering wheel. It will ask for a command.Turn on eco Drive. I would drive the car a week, same route. Gather data on the the flash stick. You needed to download the eco Drive software, on you home computer. Insert the stick into the USB computer. It would download fuel economy, and driving habits. On my Fiat Tom tom, you could pull up the same info, real time. It work on all the 500 Models, of that period.

[Fiat500USA]

Thinking about the trip computer, I remember stop and go traffic and driving through city traffic would throw the readings off.

I figure as soon as I go into the city, my goal of beating my average MPGs are going to be out the window.

[HalfPint]

I'm commuting in my Abarth, 30-35mi each way, so by now I'm getting to know how to drive it for mileage. After checking with the pump readings for a bit I've stopped bothering and just use the on-board reading, as the goal is to get the best number I can so a relative value is fine. Obviously hills hurt the mileage, but it's remarkably good at recovering on the down hill - but then again I use neutral (gravity drive) a lot. I also skip gears often, keeping the rpm down and the load up, which is more efficient.

Mostly driving for mileage is about conservation of momentum, which means anticipating and avoiding braking and accelerating - keeping a constant load on the engine is most efficient. Braking is an admission of failure! Thankfully with the Abarth I don't have to slow for corners much. I can't stand when I get stuck behind other drivers, usually braking down every hill and accelerating back up the other side, and generally braking randomly for just about everything. They must get terrible mileage.

My biggest problem is that I get bored and push the Sport button, and then redline and popping exhaust happens and the numbers go down. Actually it's remarkable how well it does even in sport mode, and if I'm in the hills I think it gets better mileage in Sport, as I can keep it in 5th - I don't load the hell out of it at low rpm, but at moderate throttle it will hold 5th better in Sport.

[samwichse]

I forgot to update this thread, but my return trip I ended up having to make an extra stop:

IMG_20220422_163504.jpg

Anyhow, the actual tank was 355.5mi/8.547gal = 41.6mpg
The MID showed 40.7mpg.

Sam

[doverosx]

I got this 1 gig flash stick from Fiat. You inserted into the USB slot, in the glove box. You had push the the speak button on the steering wheel. It will ask for a command.Turn on eco Drive. I would drive the car a week, same route. Gather data on the the flash stick. You needed to download the eco Drive software, on you home computer. Insert the stick into the USB computer. It would download fuel economy, and driving habits. On my Fiat Tom tom, you could pull up the same info, real time. It work on all the 500 Models, of that period.

I think they stopped giving out that USB stick, but I’ll give it a shot again to see if any updates fixes the issues I was having.

[map]

Thinking about the trip computer, I remember stop and go traffic and driving through city traffic would throw the readings off. I figure as soon as I go into the city, my goal of beating my average MPGs are going to be out the window.

That could be. Coasting seems to throw mine off the most. At 65, coasting down a hill, my Scangauge would hit 185 MPG on the Neon, but the Fiat reports much and maybe worse at slow speeds. Of course the SG is adjustable with each fill, so figures were closer. I wish I hadn't let that go with the Neon because my sister just gave it away.