vault backup: 2026-04-15 17:43:32
This commit is contained in:
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---
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id: 2026-04-10
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aliases: []
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title: 2026-04-10
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tags:
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- authorship/original
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- destiny/permanent
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- status/draft
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- type/periodic/daily
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dg-publish: true
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date-created: 2026-04-10T15:13:30-04:00
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weekly: "[[2026-W15]]"
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monthly: "[[2026-04]]"
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quarterly: "[[2026-Q2]]"
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yearly: "[[2026]]"
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---
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# 2026-04-10
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Made recipe: [[collards]]
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---
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id: 2026-04-14
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aliases: []
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||||
title: 2026-04-14
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tags:
|
||||
- authorship/original
|
||||
- destiny/permanent
|
||||
- status/draft
|
||||
- type/periodic/daily
|
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dg-publish: true
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date-created: 2026-04-14T15:11:48-04:00
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weekly: "[[2026-W16]]"
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monthly: "[[2026-04]]"
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quarterly: "[[2026-Q2]]"
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yearly: "[[2026]]"
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---
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# 2026-04-14
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Made recipes:
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* [[granola]]
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* [[banana-bread]]
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---
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id:
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aliases: []
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title: Voltage Drop Calculations
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tags:
|
||||
- authorship/other
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||||
- destiny/permanent
|
||||
- status/incomplete
|
||||
- topic/construction/electrical
|
||||
- type/media/article
|
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author: David A. Snyder, PE
|
||||
dg-publish: false
|
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year: 2020
|
||||
---
|
||||
# Voltage Drop Calculations
|
||||
|
||||
%%
|
||||
[E426_Voltage_Drop_Tables.pdf](https://pdhonline.com/courses/e426/E426_Voltage_Drop_Tables.pdf)
|
||||
retrieved from [pdhonline.com "Voltage Drop Calculations"](https://pdhonline.com/courses/e426/e426_new.htm)
|
||||
|
||||
PDHonline Course E426 (3 PDH)
|
||||
|
||||
Local copy saved as [[snyder_2020_voltage-drop-calculations.pdf]]
|
||||
%%
|
||||
|
||||
## Introduction
|
||||
|
||||
#### Table 1 --- Quick Guide to Voltage Drop Formulas
|
||||
|
||||
## Voltage Drop and the National Electrical Code
|
||||
|
||||
### Branch Circuits
|
||||
|
||||
### Feeders
|
||||
|
||||
### Sensitive Electronic Equipment
|
||||
|
||||
### Other Considerations
|
||||
|
||||
## Common Formulas for Voltage Drop Calculations
|
||||
|
||||
### Single-Phase Approximate Voltage Drop Formulas
|
||||
|
||||
#### Figure 1 --- Single-Phase, Two-Wire Voltage-Drop Circuit Diagram
|
||||
|
||||
#### Figure 2 --- Distributed Resistance in Conductors
|
||||
|
||||
#### Table 2 --- Derivation of the Value of K for Copper Conductors
|
||||
|
||||
#### Figure 3 --- Single-Phase, Three-Wire Voltage-Drop Circuit Diagram
|
||||
|
||||
### Three-Phase Approximate Voltage Drop Formulas
|
||||
|
||||
#### Figure 4 --- Three-Phase Wye-Connected with Neutral Voltage-Drop Circuit Diagram
|
||||
|
||||
### No Neutral Current in a Balanced Three-Phase System?
|
||||
|
||||
#### Figure 5 --- Balanced, Wye-Connected, Three-Phase, Resistance Load, with Neutral Connection
|
||||
|
||||
#### Figure 6 --- Balanced, Wye-Connected, Three-Phase 10 KW Load at 480 V
|
||||
|
||||
### √3 Relationship of Three-Phase Voltages
|
||||
|
||||
#### Figure 7 --- 480Y/277V Wye-Delta Voltage Relationship
|
||||
|
||||
#### Figure 8 --Wye-Delta Voltage Relationship --- Right Triangle Geometry
|
||||
|
||||
#### Figure 9 --- 208Y/120V Wye-Delta Voltage Relationship
|
||||
|
||||
### Why the √3 Is Used in Balanced, Three-Phase Voltage Drop Calculations
|
||||
|
||||
#### Figure 10 --- The Square Root of Three in Three-Phase Voltage-Drop Calculations
|
||||
|
||||
## Table 9 in the NEC
|
||||
|
||||
### Which Columns Are Applicable?
|
||||
|
||||
### XL (Reactance)
|
||||
|
||||
### Alternating-Current Resistance
|
||||
|
||||
### Effective Z at 0.85 PF
|
||||
|
||||
#### Table 3 --- Selected Effective Z Calculations at 0.85 PF (Ohms-to-Neutral per 1,000 feet) . 21
|
||||
|
||||
### Effective Z at Any Power Factor: Note 2 to Table 9 in the NEC
|
||||
|
||||
#### Table 4 --- Effective Z Calculations for Selected Wire Sizes at Various Power Factors (Ohms-to-Neutral per 1,000 feet)
|
||||
|
||||
## Note 2 to Table 8 in the NEC
|
||||
|
||||
### Phasor Diagrams of Resistance, Reactance, and Impedance for Conductors
|
||||
|
||||
#### Figure 11 --- Phasor Diagram of Resistance, Reactance, and Impedance for 12 AWG Copper Conductors in Steel Conduit at 0.85 PF
|
||||
|
||||
#### Figure 12 --- Phasor Diagram of Resistance, Reactance, and Impedance for 12 AWG Copper Conductors in Steel Conduit at Selected Power Factor Values
|
||||
|
||||
#### Figure 13 --- Phasor Diagram of Resistance, Reactance, and Impedance for 250 KCMIL Copper Conductors in Steel Conduit at 0.85 PF
|
||||
|
||||
#### Figure 14 --- Phasor Diagram of Resistance, Reactance, and Impedance for 500 KCMIL Copper Conductors in Steel Conduit at 0.85 PF
|
||||
|
||||
#### Figure 15 --- Phasor Diagram of Resistance, Reactance, and Impedance for 500 KCMIL Copper Conductors in Steel Conduit at Selected Power Factor Values
|
||||
|
||||
### Estimated Vdrop Derived from Impedance Phasor Diagrams
|
||||
|
||||
#### Figure 16 --- Applying 300 Amps to the Impedance Phasor Diagram for 500 KCMIL Copper Conductors in Steel Conduit at Selected Power Factor Values
|
||||
|
||||
### Estimated Vdrop, Single-Phase:
|
||||
|
||||
### Estimated Vdrop, Three-Phase:
|
||||
|
||||
## Voltage Drop Phasor Diagram in IEEE Standard 141 (Red Book)
|
||||
|
||||
#### Figure 17 --- IEEE Phasor Diagram of Voltage Drop
|
||||
|
||||
#### Figure 18 --- Vertical Components of Phasor Diagram of Voltage Drop
|
||||
|
||||
#### Figure 19 --- Triangle Formed by Vs, Vr + Estimated Vdrop, and IXcosΦ-IRsinΦ
|
||||
|
||||
#### Figure 20 --- When the Vector I * Z Really Is the Actual Vdrop
|
||||
|
||||
#### Figure 21 --- If Conductor X > R, the Error Increases as Power Factor Increases
|
||||
|
||||
## Calculating the Error Shown in the IEEE Phasor Diagram
|
||||
|
||||
#### Figure 22 --- Finding the Height h of a Circular Segment
|
||||
|
||||
### Single-Phase Formulas for Error and Actual Vdrop:
|
||||
|
||||
### Three-Phase Formulas for Error and Actual Vdrop:
|
||||
|
||||
#### Table 5 --- Error Voltage Drop Calculations for Real-World Examples in Next Section
|
||||
|
||||
## Real-World Examples
|
||||
|
||||
#### Table 6 --- Real-World Examples
|
||||
|
||||
### 10 Hp Motor at 480V/3Φ with 12 AWG Conductors
|
||||
|
||||
#### Figure 23 --- Line-to-Neutral Voltage Drop for 10 Hp Motor at 480V/3Φ with 200' of 12 AWG Conductors
|
||||
|
||||
#### Table 7 --- Line-to-Line Voltage Drop for 10 Hp Motor at 480V/3Φ with 200' of 12 AWG Conductors
|
||||
|
||||
### 15 KW Heater at 480V/3Φ with 10 AWG Conductors
|
||||
|
||||
#### Figure 24 --- Line-to-Neutral Voltage Drop for 15 KW Load at 480V/3Φ with 200' of 10 AWG Conductors
|
||||
|
||||
#### Table 8 --- Line-to-Line Voltage Drop for 15 KW Load at 480V/3Φ with 200' of 10 AWG Conductors
|
||||
|
||||
### 250 Hp Motor at 480V/3Φ with 500 KCMIL Conductors
|
||||
|
||||
#### Figure 25 --- Line-to-Neutral Voltage Drop for 250 Hp Motor at 480V/3Φ with 200' of 500 KCMIL Conductors
|
||||
|
||||
#### Table 9 --- Line-to-Line Voltage Drop for 250 Hp Motor at 480V/3Φ with 200' of 500 KCMIL Conductors
|
||||
|
||||
## Rearranging the Formulas Used for Approximate Vdrop
|
||||
|
||||
### Single-Phase Voltage Drop Formulas --- Rearranged
|
||||
|
||||
#### Table 10 --- Voltage Drop for 10 A Load at 120V/1Φ with 100' of 10 AWG Conductors
|
||||
|
||||
### Three-Phase Voltage Drop Formulas --- Rearranged
|
||||
|
||||
## Other Considerations
|
||||
|
||||
### Increase Equipment Grounding Conductor Size
|
||||
|
||||
### Increase Grounded (Neutral) Conductor Size
|
||||
|
||||
### Verify Wire Size and Quantity Capacity of Terminations at Both Ends
|
||||
|
||||
### Verify Conduit Size
|
||||
|
||||
### Rule-of-Thumb
|
||||
|
||||
### Converting Formulas from Single-Phase to Three-Phase
|
||||
|
||||
#### Table 11 --- Voltage Drop for 10 A Load at 120V/1Φ with 120' of 12 AWG Conductors
|
||||
|
||||
#### Table 12 --- Voltage Drop for 10 A Load at 208V/3Φ with 208' of 12 AWG Conductors
|
||||
|
||||
#### Table 13 --- Voltage Drop for 10 A Load at 277V/1Φ with 277' of 12 AWG Conductors
|
||||
|
||||
#### Table 14 --- Voltage Drop for 10 A Load at 480V/3Φ with 480' of 12 AWG Conductors
|
||||
|
||||
## In Closing
|
||||
|
||||
## Abbreviations
|
||||
|
||||
## Additional Reading
|
||||
@@ -0,0 +1,32 @@
|
||||
---
|
||||
id: 2026-04-15T09:18:45-04:00
|
||||
aliases: []
|
||||
title: 2026-04-15 09:18:45
|
||||
tags:
|
||||
- authorship/original
|
||||
- destiny/permanent
|
||||
- status/draft
|
||||
- type/periodic/timestamped
|
||||
dg-publish: true
|
||||
date-created: 2026-04-15T09:18:45-04:00
|
||||
daily: "[[2026-04-15]]"
|
||||
weekly: "[[2026-W16]]"
|
||||
monthly: "[[2026-04]]"
|
||||
quarterly: "[[2026-Q2]]"
|
||||
yearly: "[[2026]]"
|
||||
---
|
||||
# 2026-04-15 09:18:45
|
||||
|
||||
[[snyder_2020_voltage-drop-calculations]]
|
||||
closes with this string of [Morse code](https://en.wikipedia.org/wiki/Morse_code):[^1]
|
||||
|
||||
```morse
|
||||
.-. . ... .--. . -.-. - ..-. ..- .-.. .-.. -.-- ... ..- -... -- .. - - . -..
|
||||
```
|
||||
|
||||
[^1]: Original characters were converted to ASCII, whitespace normalized.
|
||||
The sequence reads "RESPECTFULLYSUBMITTED".
|
||||
|
||||
A Morse code translator,
|
||||
including parser and beeper,
|
||||
would be a great beginner programming project.
|
||||
@@ -0,0 +1,34 @@
|
||||
---
|
||||
id: 2026-04-15T11:00:38-04:00
|
||||
aliases: []
|
||||
title: 2026-04-15 11:00:38
|
||||
tags:
|
||||
- authorship/original
|
||||
- destiny/permanent
|
||||
- status/draft
|
||||
- type/periodic/timestamped
|
||||
dg-publish: true
|
||||
date-created: 2026-04-15T11:00:38-04:00
|
||||
daily: "[[2026-04-15]]"
|
||||
weekly: "[[2026-W16]]"
|
||||
monthly: "[[2026-04]]"
|
||||
quarterly: "[[2026-Q2]]"
|
||||
yearly: "[[2026]]"
|
||||
---
|
||||
# 2026-04-15 11:00:38
|
||||
|
||||
## Equipment Grounding Conductor Sizing
|
||||
|
||||
[[virginia-live-casino-and-hotel]]
|
||||
one-lines specify ~~a feeder~~ as
|
||||
`(6) SETS OF: 4#600, 1#450G, 4"C.`
|
||||
|
||||
The use of 450kcmil for the EGC is strange:
|
||||
|
||||
* It is not a size specified by
|
||||
[[nfpa-70_250_grounding#Table 250.122 Minimum Size Equipment Grounding Conductors for Grounding Raceway and Equipment|Table 250.122]]
|
||||
|
||||
* it is a non-standard size anyway,
|
||||
not appearing in [[nfpa-70_ch09|Chapter 9]] tables,
|
||||
the [[neca-mlu]],
|
||||
or our Accubid database.
|
||||
@@ -0,0 +1,38 @@
|
||||
---
|
||||
id: 2026-04-15T14:54:00-04:00
|
||||
aliases: []
|
||||
title: 2026-04-15 14:54:00
|
||||
tags:
|
||||
- authorship/original
|
||||
- destiny/permanent
|
||||
- status/draft
|
||||
- type/periodic/timestamped
|
||||
dg-publish: true
|
||||
date-created: 2026-04-15T14:54:00-04:00
|
||||
daily: "[[2026-04-15]]"
|
||||
weekly: "[[2026-W16]]"
|
||||
monthly: "[[2026-04]]"
|
||||
quarterly: "[[2026-Q2]]"
|
||||
yearly: "[[2026]]"
|
||||
---
|
||||
# 2026-04-15 14:54:00
|
||||
|
||||
## Working While Standing for Focus
|
||||
|
||||
Yesterday Baker (our current project engineer)
|
||||
asked if I use the standing mode of my desk often.
|
||||
I told him I really didn't,
|
||||
except to show multiple people something on my screens.
|
||||
Thinking of [[kahneman_2011_thinking]],
|
||||
I stated that this was a conscious choice
|
||||
because one can not think as deeply while standing as while sitting.[^1]
|
||||
|
||||
[^1]: This is mostly justification for a preexisting behavior.
|
||||
I think the largest part of my tendency
|
||||
is that I don't like people watching me work.
|
||||
|
||||
He clarified that he did this in order to _focus_,
|
||||
which I have heard before but never gave much credit.
|
||||
I then made the now obvious connection
|
||||
that impairing deep thinking is exactly the method
|
||||
by which standing improves focus.
|
||||
@@ -0,0 +1,65 @@
|
||||
---
|
||||
id: 2026-04-15T15:15:07-04:00
|
||||
aliases: []
|
||||
title: 2026-04-15 15:15:07
|
||||
tags:
|
||||
- authorship/original
|
||||
- destiny/permanent
|
||||
- status/draft
|
||||
- type/periodic/timestamped
|
||||
- topic/meta
|
||||
dg-publish: true
|
||||
date-created: 2026-04-15T15:15:07-04:00
|
||||
daily: "[[2026-04-15]]"
|
||||
weekly: "[[2026-W16]]"
|
||||
monthly: "[[2026-04]]"
|
||||
quarterly: "[[2026-Q2]]"
|
||||
yearly: "[[2026]]"
|
||||
---
|
||||
# 2026-04-15 15:15:07
|
||||
|
||||
## Considering the Role of Daily Notes in My Vault
|
||||
|
||||
I think daily notes still have a good use case for me,
|
||||
but I'm not sure of the details.
|
||||
|
||||
What content should be daily and what timestamped
|
||||
is a matter of the logic of links and tags.
|
||||
|
||||
Daily notes should only contain content _about that day_.
|
||||
|
||||
What's tricky about this is that
|
||||
|
||||
### What Daily Notes Should Contain
|
||||
|
||||
#### Tracking
|
||||
|
||||
```
|
||||
Made recipe: [[granola]]
|
||||
```
|
||||
|
||||
### What Daily Notes Should Not Contain
|
||||
|
||||
#### Synthesis
|
||||
|
||||
The utility of timestamped notes
|
||||
is that, since the topic is self contained,
|
||||
the note's tags apply to all content within it.
|
||||
Contrast with my previous system,
|
||||
more like a traditional diary,
|
||||
where synthesis for myriad topics
|
||||
was grouped arbitrarily
|
||||
by the day I happened to make a connection.
|
||||
|
||||
### What Daily Notes Could Contain
|
||||
|
||||
#### Objective Descriptions of Events
|
||||
|
||||
I see two options, neither attractive:
|
||||
|
||||
##### Option 1: Prose
|
||||
|
||||
because it would be very boring to write.
|
||||
|
||||
##### Option 2: Standard Terse Format
|
||||
|
||||
@@ -0,0 +1,66 @@
|
||||
---
|
||||
id: 2026-04-15T15:59:02-04:00
|
||||
aliases: []
|
||||
title: 2026-04-15 15:59:02
|
||||
tags:
|
||||
- authorship/original
|
||||
- destiny/permanent
|
||||
- status/draft
|
||||
- type/periodic/timestamped
|
||||
dg-publish: true
|
||||
date-created: 2026-04-15T15:59:02-04:00
|
||||
daily: "[[2026-04-15]]"
|
||||
weekly: "[[2026-W16]]"
|
||||
monthly: "[[2026-04]]"
|
||||
quarterly: "[[2026-Q2]]"
|
||||
yearly: "[[2026]]"
|
||||
---
|
||||
# 2026-04-15 15:59:02
|
||||
|
||||
Probably the most obviously helpful convention
|
||||
of [[note-taking]]/[[personal-knowledge-management]]
|
||||
that I use in [[this-notebook]]
|
||||
is how I journal my mistakes.
|
||||
|
||||
1. The **mistake**,
|
||||
the objectionable actions taken
|
||||
that lead to the problem.
|
||||
|
||||
2. The **problem**,
|
||||
the undesirable state resulting from the mistake
|
||||
This includes the immediate outcome
|
||||
and, if applicable, the cost of correction.
|
||||
|
||||
3. The **rationale**,
|
||||
the reason for the mistake.
|
||||
|
||||
***
|
||||
|
||||
The intent is that by recording this conflict
|
||||
in as much detail as practical
|
||||
I can determine what actions I can take
|
||||
to prevent the most pain from future mistakes.
|
||||
|
||||
***
|
||||
|
||||
Rationale is the most important part of the entry.
|
||||
It's not helpful to say
|
||||
If that's truly what seems to be the cause,
|
||||
consider your state at the time:
|
||||
Were you mentally exhausted?
|
||||
If so, was it due to workload or issues at home?
|
||||
|
||||
"I was being stupid," and "I wasn't thinking,"
|
||||
are not informative rationales.
|
||||
"I will try harder," and "I will pay more attention"
|
||||
are not actionable plans.
|
||||
|
||||
***
|
||||
|
||||
"Mistake" may be a misnomer,
|
||||
because acceptability is not objective.
|
||||
For example:
|
||||
two [[conest]] senior estimators
|
||||
may disagree on the acceptability of a certain [[heuristics|heuristic]].
|
||||
It may still be useful to record criticism from the more stringent senior
|
||||
as a mistake, even if their position is less popular.
|
||||
@@ -0,0 +1,33 @@
|
||||
---
|
||||
id: 2026-04-15T17:31:57-04:00
|
||||
aliases: []
|
||||
title: 2026-04-15 17:31:57
|
||||
tags:
|
||||
- authorship/original
|
||||
- destiny/permanent
|
||||
- status/draft
|
||||
- type/periodic/timestamped
|
||||
dg-publish: true
|
||||
date-created: 2026-04-15T17:31:57-04:00
|
||||
daily: "[[2026-04-15]]"
|
||||
weekly: "[[2026-W16]]"
|
||||
monthly: "[[2026-04]]"
|
||||
quarterly: "[[2026-Q2]]"
|
||||
yearly: "[[2026]]"
|
||||
---
|
||||
# 2026-04-15 17:31:57
|
||||
|
||||
A peer, not intending to,
|
||||
convinced me I should buy my next car
|
||||
as much over email as possible.
|
||||
|
||||
Consider my requirements for a new vehicle:
|
||||
|
||||
* Reliable make: Honda or Toyota
|
||||
* Compact [body style](https://en.wikipedia.org/wiki/Car_body_style):
|
||||
Sedan, Crossover, or Hatchback
|
||||
(really just not a pickup or SUV)
|
||||
|
||||
I thought that these requirements were too open
|
||||
to make research like peer suggested impractical,
|
||||
but I realized now that they narrow my selection considerably.
|
||||
Reference in New Issue
Block a user