Fiat 500 Forum banner
21 - 40 of 55 Posts

·
Registered
2013 FIAT 500e
Joined
·
3,179 Posts
Discussion Starter · #22 ·
... I don’t think they wanted to spend anymore money on this car they could’ve gotten a lot more highway range by covering the rear muffler area...
Ya, they spent a bunch of money on VISIBLE aero, which doesn't seem to make as much difference, like E-specific staggered-width aero wheels. Then they spent more money on the "sport" trim wheels, which are actually less aero but with the same range specs. They spent money to BARELY change the mirror covers & wing (pre-existing Abarth wing would have been fine).

It does seem their money was well spent on the rubber airdam, however & in my opinion they wasted money* that would have been better spent on decent shocks & underbelly cover, but at least those aren't all that hard/expensive to DIY.

*Wasted on things like motor cover, acoustic windshield, speed-sensitive wiper delay, "auto" hvac button... (it's still auto-temp without it)
 

·
Registered
2013 FIAT 500e
Joined
·
3,179 Posts
Discussion Starter · #23 · (Edited)
The idea seems to be redirect that front air around the wheels to reduce the impact of turbulence from wheels. I think Abarths have this... My simpleton thought is what if you just slap on of those bumper covers on...
My own simpleton thought on this idea is maybe just add an "open-ended box" to our existing bumper cover, kind of like the pic below without the ribs. Also...

It also does not have a real diffuser. Something that always annoyed me. I need one for the E, if it helps efficiency.
5-7% efficiency increase by covering under rear, according to the link above.
12-15% efficiency increase from lowering 2", according to twinturboz.


Click to enlarge:
Automotive exterior Bumper Vehicle Car Vehicle door
 

·
Registered
2017 Fiat 500e (Billet Argento), 2015 VW Golf Sportwagen TSI 5MT (Tungsten Silver), 2002 Honda VFR
Joined
·
828 Posts
I’d also like to note there is much less wind noise lowered, I don’t know how that makes any sense but at 75-80 there was quiet a bit of wind/buffeting noises stock, now I don’t even notice the noises at all, so strange. What I do notice now is door seals/weatherstripping or something making creeking or jiggling noises entering driveways angled or driving slowly over bumpy roads. Time to lube up the door seals I guess.
 

·
Registered
2013 FIAT 500e
Joined
·
3,179 Posts
Discussion Starter · #25 ·
It takes energy to create sound. Wind noise is a sign of energy lost to drag. Your new lower drag = lower noise.

Other things will then seem louder by comparison.
 

·
Registered
2017 Fiat 500e (Billet Argento), 2015 VW Golf Sportwagen TSI 5MT (Tungsten Silver), 2002 Honda VFR
Joined
·
828 Posts
It takes energy to create sound. Wind noise is a sign of energy lost to drag. Your new lower drag = lower noise.

Other things will then seem louder by comparison.
One strong positive that I don’t regret is freeway straight line tracking, holy cow wayyy less steering correction needed to drive straight before I would ping pong back and forth stying to keep her centered making me look like a drunk or inept driver I’m sure. The car just feels more planted and secure. This whole time I thought it was either the tire or something to do with such a short wheelbase tiny car thing.
 

·
Registered
Joined
·
30 Posts
I think Fiat did pretty well with the aero. They probably had a set target for improvements over the gas siblings and a tight budget. And as you mentioned. Once you loose the loud gas engine, other sounds become noticeable so they chose to spend some budget on reducing the cabin noise.
The rear belly cover looks to be low hanging fruit for aero improvement and noise reduction. I will be ordering one this week. Will for sure post pics. Great input here. Thanks.
 

·
Registered
2013 FIAT 500e
Joined
·
3,179 Posts
Discussion Starter · #30 ·
Please also post if you see any range improvement. If I remember right, your car is also lowered, so it would be interesting to see if the cover makes more difference or less, compared to it's 5-7% improvement at stock height.

twinturboz wrote about a FRONT belly pan "all the way up to the rubber air dam edge to edge all the way back to the front battery section.", HOWEVER, apparently the 2" height reduction now makes the fans & even A/C work overtime, so I wonder how that will be affected by blocking ALL of the radiators' exit airflow.
 

·
Registered
2017 Fiat 500e (Billet Argento), 2015 VW Golf Sportwagen TSI 5MT (Tungsten Silver), 2002 Honda VFR
Joined
·
828 Posts
There will be a small section just before the battery pack that is open for it to get sucked out. The pan won’t exceed beyond farther back what the factory gasser covers, the difference is mine will go all the way up as a single piece and connect with the fender liners.
 

·
Registered
2013 FIAT 500e
Joined
·
3,179 Posts
Discussion Starter · #32 ·
Maybe fine as long as the opening is about the same total size as the front opening. Location-dependent though, based on where on the underbody the air pressure/flow is optimal with the cover in place.
 

·
Registered
Joined
·
30 Posts
Please also post if you see any range improvement. If I remember right, your car is also lowered, so it would be interesting to see if the cover makes more difference or less, compared to it's 5-7% improvement at stock height.

twinturboz wrote about a FRONT belly pan "all the way up to the rubber air dam edge to edge all the way back to the front battery section.", HOWEVER, apparently the 2" height reduction now makes the fans & even A/C work overtime, so I wonder how that will be affected by blocking ALL of the radiators' exit airflow.
For sure, I’m curious as well. I’ll post my findings. My daily commute is very short under 4 miles all light to light driving. And take the car on the highway only about once a month or less so I might not see a difference for a while if any. I will only get the rear one for now and go from there.
 

·
Registered
2017 Fiat 500e (Billet Argento), 2015 VW Golf Sportwagen TSI 5MT (Tungsten Silver), 2002 Honda VFR
Joined
·
828 Posts
For sure, I’m curious as well. I’ll post my findings. My daily commute is very short under 4 miles all light to light driving. And take the car on the highway only about once a month or less so I might not see a difference for a while if any. I will only get the rear one for now and go from there.
In my use case my 70 miles a day round trip is made up of 85% freeway speeds 70-80mph so every bit helps.
 

·
Registered
Joined
·
101 Posts
I think Fiat did pretty well with the aero.
6.3% gain over the Pop putting it at 0.311 Cd which isn't great. For context the Bolts lead designer said their 2016 models 0.32 Cd was "a disaster." Most EVs and eco conscious vehicles do better and every one I looked at has a mostly if not perfect flat belly. Beyond the belly and grille I suspect the problem is more with the front shape which is much harder to change.
 

·
Registered
2017 Fiat 500e (Billet Argento), 2015 VW Golf Sportwagen TSI 5MT (Tungsten Silver), 2002 Honda VFR
Joined
·
828 Posts
6.3% gain over the Pop putting it at 0.311 Cd which isn't great. For context the Bolts lead designer said their 2016 models 0.32 Cd was "a disaster." Most EVs and eco conscious vehicles do better and every one I looked at has a mostly if not perfect flat belly. Beyond the belly and grille I suspect the problem is more with the front shape which is much harder to change.
Yea ideally should be 0.28 or better for efficiency.
 

·
Registered
2013 FIAT 500e
Joined
·
3,179 Posts
Discussion Starter · #37 · (Edited)
Hyundai ioniq at 0.24 is supposedly still the most efficient car. Period. Yes, part of the efficiency may be mechanical (like motor, inverter & regen efficiency), but...

Carrl says 500e is 0.311

Lowered 2" seems to be up to 15% better, so 0.264

Add rear belly pan for 7% better at .246

Not bad!

Now consider that drag coefficient gets multiplied by frontal area for total drag. 500e is 2" taller but EIGHT inches narrower, so around 9% less frontal area, for lower total drag.
 

·
Registered
2017 Fiat 500e (Billet Argento), 2015 VW Golf Sportwagen TSI 5MT (Tungsten Silver), 2002 Honda VFR
Joined
·
828 Posts
Yea but the shoe shape of the 500 isn’t very aero in any regards despite its small footprint and frontal, exposed wiper arms area plus the huge mirrors definitely don’t help drag. I’d like to know what the miles per kw the ionique gets because I can score over 5.0+ per kw relatively easily on this car on highway, if I drop my speeds to Prius level possibly 6 per kw. I’ve gotten that simply drafting a uhaul before even lowering.
 

·
Registered
Joined
·
101 Posts
I’d like to know what the miles per kw the ionique
This video talks about efficiency a bit but in a less structured way than he normal does. According to his data the Ioniq is more efficient even at higher speeds :eek:. His spreadsheet has data from many EV models and conditions. While not perfect, it's interesting to hear and see data from someone who tests all kinds of EVs.
 

·
Registered
2013 FIAT 500e
Joined
·
3,179 Posts
Discussion Starter · #40 · (Edited)
Yea ideally should be 0.28 or better for efficiency... but the shoe shape of the 500 isn’t very aero in any regards despite its small footprint and frontal, exposed wiper arms area plus the huge mirrors definitely don’t help drag...
My point was that with just 2" of lowering we DO HAVE 0.28 or better.

Nearly everyone I ask at the local public chargers gets more than EPA efficiency in the 500e. My friend who used to work at Hyundai & talk to the ioniq testers & engineers said they all got better than EPA. But I met an ioniq driver yesterday who said he didn't.

As for "more efficient at higher speed", I read* that motors/gearing of low-range commuter cars like ours were optimized for their expected lower city speeds. That increases the already-large range difference between city & highway speeds. As EV's ranges increased beyond "city-only" use, they've been optimized for higher speeds, which compensates somewhat for the huge difference in aerodynamic drag between highway & city speeds.

* at PushEVs, I think.
 
21 - 40 of 55 Posts
Top