Add Yours: VW ID. Buzz Owner's Registry

25% reduction in range with roof box

3179 Views 14 Replies 7 Participants Last post by ID4 GTX, Oct 31, 2021

jongarusa

Discussion Starter · Jun 4, 2021

All,

So i completed a number of trips to confirm my results, the total range with my particular box. The result was that consumption went from 3.1 m/KWH to 2.6 m/KWH. The predicted range was 200 miles. Data thats important. I was using the official ID4 roofbars, with a Thule Pulse L box --- Thule Pulse

For 240 of the 300 or so miles I kept a steady 65-75 mph speed, with the AC on. There was approx 150lbs of gear in the box. One leg of the trips was just bloody awful traffic, with some higher speed moments. There was a good mix of North/south/east/west to create variables with wind. (I think new EV owners are going to be surprised how much of an impact wind has on range)

Yes I could use a smaller box, but thats the one we use with the Pacifica Minivan. I have done 1000's of miles with the roof box on that vehicle, and record a drop in efficiency of about 17% with that combo. That vehicle is noticeably less aerodynamic.

You can learn more here, and hear a rant or three about california drivers here

Reactions: 3

1 - 15 of 15 Posts

Nai3t

· #2 · Jun 4, 2021

Big difference between 65 and 75 mph, even without the box on the roof. It'd be interesting to see that tested out.

By the numbers, the Pacifica isn't too big of a dog when it comes to aero competed to the ID.4

Reactions: 2

ExCivilian

· #3 · Jun 4, 2021 (Edited)

Nai3t said:
By the numbers, the Pacifica isn't too big of a dog when it comes to aero competed to the ID.4

That or it starts out less efficient so the box doesn't change much

John, from your travels it looks like you might be from Oregon? Do keep in mind that while you'll experience 2 lane (single direction) highways throughout OR and much of rural, northern CA, the majority of drivers (and our laws) are focused on 3 lane (single direction) highway driving. The right lane is generally reserved for on/off freeway, driving below the posted speed limit, and large trucks/towing--it's not a primary travel lane like it's supposed to be in OR. The middle lane is analogous to your OR right lane with both our states' left lanes reserved for "passing" (by law, not necessarily practice).

Nai3t

· #4 · Jun 4, 2021

Yeah, you guys reminded me to take into account frontal area, but I imagine the 2 are similar in that respect, and .28 vs. .30 drag coefficients.

jongarusa

Discussion Starter · #5 · Jun 4, 2021

ExCivilian said:
That or it starts out less efficient so the box doesn't change much

John, from your travels it looks like you might be from Oregon? Do keep in mind that while you'll experience 2 lane (single direction) highways throughout OR and much of rural, northern CA, the majority of drivers (and our laws) are focused on 3 lane (single direction) highway driving. The right lane is generally reserved for on/off freeway, driving below the posted speed limit, and large trucks/towing--it's not a primary travel lane like it's supposed to be in OR. The middle lane is analogous to your OR right lane with both our states' left lanes reserved for "passing" (by law, not necessarily practice).

I live in the bay area, but as you might be able to tell, I am originally from Britain. Yes - trucks/vehicles with a designated maximum of 55 must use the right lane, but that does not mean others cant use it. We are all meant to stay right, except for passing.

jongarusa

Discussion Starter · #6 · Jun 4, 2021

Nai3t said:
Big difference between 65 and 75 mph, even without the box on the roof. It'd be interesting to see that tested out.

By the numbers, the Pacifica isn't too big of a dog when it comes to aero competed to the ID.4

I had cruise control set to 75, as I would a roadtrip. I only slowed as required for traffic. I was there 90% of the time. Based on my earlier non roof box numbers, I am happy with AC on, 72mph and 235 miles of range as my guide for road trips.

ExCivilian

· #7 · Jun 4, 2021

jongarusa said:
We are all meant to stay right, except for passing.

What I wrote was basically lifted from the DMV handbook. Right lane travel is only appropriate on two lane highways (in CA). In contrast, OR will cite drivers who travel in the left lane. Here's a direct quote:

Drive in the lane with the smoothest flow of traffic. If you can choose among three lanes, pick the middle lane for the smoothest driving. To drive faster, pass, or turn left, use the left lane. When you choose to drive slowly, enter or exit traffic on the right, turn right, park, or move off the road, use the right lane. If there are only two lanes in your direction, pick the right lane for the smoothest driving.

www.dmv.ca.gov

Lane Control - California DMV

Examples of lane markings (1) Solid yellow line: No passing if solid yellow line is on your side.(2) Double solid lines: DO NOT pass.(3) Broken yellow line: May pass if movement can be made safely. Line Colors Solid yellow lines mark the center of a road used for two-way traffic. Broken yellow...

www.dmv.ca.gov

jongarusa

Discussion Starter · #8 · Jun 5, 2021

ExCivilian said:
What I wrote was basically lifted from the DMV handbook. Right lane travel is only appropriate on two lane highways (in CA). In contrast, OR will cite drivers who travel in the left lane. Here's a direct quote:

Lane Control - California DMV

Examples of lane markings (1) Solid yellow line: No passing if solid yellow line is on your side.(2) Double solid lines: DO NOT pass.(3) Broken yellow line: May pass if movement can be made safely. Line Colors Solid yellow lines mark the center of a road used for two-way traffic. Broken yellow...

www.dmv.ca.gov

NOOOOOOOOOO !!!! This is why you cant have an empire !!! Whoever wrote that is probably a Kardashian.......

Reactions: 3

Lxtruong

· #9 · Jun 5, 2021

Man that's a pretty big hit. I'm getting a cargo carrier for the hitch (https://www.amazon.com/dp/B00JF53ZE...abc_7GG9V40T76XCER2SJZ04?_encoding=UTF8&psc=1) and your #s definitely make me glad I'm going that route.

deepskier

· #10 · Jun 5, 2021

I saw somewhere that roof boxes are actually more aerodynamic if you install them backwards with the thick part in front. Think of how an airplane wing is shaped.

Found it

electrek.co

Tesla Model 3 with roof-rack box gets much better range if you flip box around

A Tesla Model 3 owner figured out that his electric car is much more efficient with a roof-rack box gets...

electrek.co

Reactions: 2

ChristophW

· #11 · Jun 5, 2021

Lxtruong said:
Man that's a pretty big hit. I'm getting a cargo carrier for the hitch (https://www.amazon.com/dp/B00JF53ZE...abc_7GG9V40T76XCER2SJZ04?_encoding=UTF8&psc=1) and your #s definitely make me glad I'm going that route.

I’m curious what you will find. We have a few preliminary numbers for bike racks on here somewhere (not great, if I recall correctly, but not terrible). I expect the disturbance to the smooth air flow off the spoiler to have a noticeable impact on range. The question is: Will your cargo box do better than a roof box? Do keep in mind that @jongarusa’s roofbox is rather large.

jongarusa

Discussion Starter · #12 · Jun 5, 2021

So I have an 18 inch cargo carrier. It dropped about 10 miles rAnge, but I didn't do enough miles to confirm.

Lxtruong

· #13 · Jun 5, 2021

jongarusa said:
So I have an 18 inch cargo carrier. It dropped about 10 miles rAnge, but I didn't do enough miles to confirm.

10 miles on the guess o meter? Or observed 10 miles.

jongarusa

Discussion Starter · #14 · Jun 6, 2021

Lxtruong said:
10 miles on the guess o meter? Or observed 10 miles.

10 miles drop on the GOM, however, There was a .1 increase in consumption, on a route I use regulary, so I would put it accurate, with a small margin of error. All highway speeds.

JG

Reactions: 2

ID4 GTX

· #15 · Oct 31, 2021 (Edited)

jongarusa said:
All,

So i completed a number of trips to confirm my results, the total range with my particular box. The result was that consumption went from 3.1 m/KWH to 2.6 m/KWH. The predicted range was 200 miles. Data thats important. I was using the official ID4 roofbars, with a Thule Pulse L box --- Thule Pulse

For 240 of the 300 or so miles I kept a steady 65-75 mph speed, with the AC on. There was approx 150lbs of gear in the box. One leg of the trips was just bloody awful traffic, with some higher speed moments. There was a good mix of North/south/east/west to create variables with wind. (I think new EV owners are going to be surprised how much of an impact wind has on range)

Yes I could use a smaller box, but thats the one we use with the Pacifica Minivan. I have done 1000's of miles with the roof box on that vehicle, and record a drop in efficiency of about 17% with that combo. That vehicle is noticeably less aerodynamic.

You can learn more here, and hear a rant or three about california drivers here

I have same Roofbox setup (large sized thule) and standard id4 roofbars. I observered with our old gasoline car that roofbox reduced range was 10% in avarge speed 65 Mph, I will reply with new data of ID4 + roofbox after long testdrive. My goal is to set in advanced settings in ABRP a comparable airspeed value when roofbox included in trip planning, so you get more accurat range calculations in variation of speed.

Reactions: 1

1 - 15 of 15 Posts

This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.