ETENWOLF S3 Cordless Tire Inflator — Inflation Speed Test Report (215/55R17, 25–35 psi)

Document Overview

Key Findings The ETENWOLF S3 cordless tire inflator successfully inflated a 215/55R17 passenger car tire from 25 psi to 35 psi across all 20 recorded runs on two production units, with inflation times consistently ranging from 1 minute 37 seconds to 1 minute 58 seconds.…

Document type

Test Report

Prepared by

Daniel Wright

Published

July 22, 2026

Last reviewed

July 22, 2026

Topics

Motor Performance

Key Findings

The ETENWOLF S3 cordless tire inflator successfully inflated a 215/55R17 passenger car tire from 25 psi to 35 psi across all 20 recorded runs on two production units, with inflation times consistently ranging from 1 minute 37 seconds to 1 minute 58 seconds.

• Product: ETENWOLF S3 Cordless Tire Inflator
• Test Type: Motor Performance — Inflation Speed
• Target Range: 25 psi → 35 psi (10 psi delta)
• Tire Spec: 215/55R17 passenger car tire
• Units Tested: 2 production samples (Unit 4#, Unit 5#)
• Runs per Unit: 10 consecutive inflation cycles
• Fastest Run: 1 min 37 sec (Unit 5#, Run 8)
• Slowest Run: 1 min 58 sec (Unit 4#, Run 6)
• Overall Average: approx. 1 min 49 sec across all 20 runs

Test Overview

Test Equipment & Setup

Test Procedure

1. Pre-Test: Verify the S3 unit is fully charged before beginning the test sequence.
2. Pre-Test: Mount the inflation nozzle to the 215/55R17 tire valve stem and confirm a secure, leak-free connection.
3. Pre-Test: Deflate the tire to 25 psi (starting pressure) before each run and confirm with a calibrated gauge.
4. Procedure: Set the S3 target pressure to 35 psi using the onboard digital display.
5. Procedure: Start the timer simultaneously with pressing the inflation start button.
6. Procedure: Allow the unit to run continuously until the auto-stop triggers at 35 psi; stop the timer at the moment of auto-shutoff.
7. Procedure: Record the elapsed time in minutes and seconds format.
8. Procedure: Deflate tire back to 25 psi and repeat for 10 consecutive runs per unit.
9. Procedure: Repeat the full 10-run sequence for the second sample unit.
10. Post-Test: Compile all 20 run times and calculate per-unit and overall averages.
11. Acceptance Criteria: All inflation times must fall within a consistent, repeatable range demonstrating stable motor performance across successive cycles.

Test Data & Results

The table below records all 20 inflation runs for both Unit 4# and Unit 5#, inflating a 215/55R17 tire from 25 psi to 35 psi.

Observations:

• Unit 4# times ranged from 1:38 to 1:58, with a calculated average of approximately 1:51.
• Unit 5# times ranged from 1:37 to 1:55, with a calculated average of approximately 1:48.
• Both units show a moderate warm-up effect in runs 1–7, with slightly faster times observed in runs 8–9, consistent with thermal cycling behavior in brushless motor compressors.
• No anomalous stops, pressure leaks, or auto-shutoff failures were recorded across all 20 runs.
• Performance between the two units is closely matched, indicating consistent manufacturing quality for this production batch.

Conclusion

Document Information

Frequently Asked Questions

How long does the ETENWOLF S3 take to inflate a 215/55R17 tire from 25 to 35 psi?

In controlled testing across 20 consecutive runs on two production units, the S3 inflated a 215/55R17 passenger car tire from 25 psi to 35 psi in approximately 1 minute 37 seconds to 1 minute 58 seconds, with an overall average of around 1 minute 49 seconds. Actual times may vary slightly depending on ambient temperature, battery charge level, and tire condition.

Why do inflation times vary across repeated runs on the same unit?

A moderate variation of 15–20 seconds across runs is normal and expected. Brushless motor compressors generate heat during operation, and thermal buildup can slightly affect compression efficiency. The data shows a typical pattern where runs 4–7 are marginally slower, while runs 8–9 often recover as the motor reaches a stable operating temperature. This variation is within acceptable performance tolerances.

Does the S3 auto-stop when it reaches the target pressure?

Yes. The S3 features an automatic shutoff that cuts the motor as soon as the tire reaches the preset target pressure — in this test, 35 psi. All 20 test runs confirmed reliable auto-shutoff behavior with no overrun events recorded.

Are the two tested units consistent with each other?

Yes. Unit 4# averaged approximately 1 minute 51 seconds and Unit 5# averaged approximately 1 minute 48 seconds — a difference of only 3 seconds. This close agreement indicates tight manufacturing consistency for this production batch of the S3.

Related Products

• ETENWOLF S3 Cordless Tire Inflator — Product Page

Other test reports for the S3 model:

• Sheet: 25-35psi打气时间 — 25–35 psi Inflation Time (current report)