Chongqing is a representative Chinese city facing the dual challenge of "acid rain + fog." The annual acid rain frequency exceeds 50%, and autumn/winter foggy spells can last 20–30 days. Many car owners overlook how this environment corrodes vehicle flooring. Today we share 3 real cases.
▲ Real-shot modified flooring from 3 Cases of Car Floor Corrosion by Acid Rain and Fog in Chongqing
1. The Unique Character of Chongqing's Environment
Chongqing's geography and climate have several distinguishing features:
- Basin topography: Poor air circulation makes it hard for pollutants to disperse
- High humidity: Annual average humidity of 75%–85%
- High acid rain frequency: Rainfall with a pH below 5.6 accounts for more than 50%
- Heavy autumn/winter fog: Foggy days with visibility below 1km average 30–50 days a year
Acid rain (pH<5.6) corrodes vehicle flooring slowly over the long term—each individual contact shows no visible change, but obvious corrosion marks appear after 3–5 years.
The 3 cases in hand were real modification issues reported by local Chongqing car owners between 2023 and 2025 .
2. Case 1: GAC Trumpchi M8 Edge Delamination
Owner: Yubei District, Chongqing; M8 modified 2 years ago
Symptoms: Delamination of the laminate film along the edge of the second-row welcome step, with white powdery corrosion forming on the aluminium surface
Root cause:
- The modification shop used a UV printing process (film thickness 30–50 microns)
- Chongqing acid rain commonly has a pH below 4.5
- The adhesive layer between the UV coating and the aluminium plate gradually breaks down in the acidic environment
Repair solution:
- Strip the delaminated area and re-bond a HPL laminate film
- Apply sealant along the edges to keep rainwater out
- Fit a water deflector on the welcome step
Repair cost: 1500 yuan (materials + labour)
Lesson: HPL lamination resists acid far better than UV coatings. Chongqing owners choosing flooring should prioritise HPL processes.
3. Case 2: Denza D9 Green Stains at Third-Row Seams
Owner: Jiangbei District, Chongqing; D9 modified 3 years ago
Symptoms: Light green spots appearing at the third-row floor seams that cannot be wiped off
Root cause:
- The modification shop used a recycled PE core material
- Under Chongqing's high humidity, the recycled material absorbs water and swells
- Acid rainwater seeping into the seam reacts with impurities in the core, producing copper-rust-coloured spots (commonly called "green rust")
Repair solution:
- Remove the third-row floor
- Re-install with virgin PE core material + HPL laminate film
- Apply sealant at the seams and add extra clips
Repair cost: 3500 yuan (including full third-row floor replacement)
Lesson: The PE core must be virgin material—recycled stock releases metallic impurities in acidic environments, causing rust spots.
4. Case 3: Voyah Dreamer Laminate Film Blistering
Owner: Jiulongpo District, Chongqing; Dreamer modified 1.5 years ago
Symptoms: Circular blisters of 3–5cm² appearing in the first-row driver's-side laminate film
Root cause:
- The modification shop used bamboo-fibre aviation aluminium floor
- The bamboo-fibre substrate absorbs water and swells in high humidity
- The adhesive layer between the laminate film and the substrate fails
Repair solution:
- Strip the blistered sections
- Re-bond aviation aluminium floor with HPL (not bamboo fibre)
- Apply sealant at the seams
Repair cost: 2800 yuan
Lesson: Bamboo-fibre aviation aluminium floor is not recommended in Chongqing—substrate swelling from water absorption is inevitable.
5. Five Key Points for Chongqing Owners Choosing Flooring
Key Point 1: The Process Must Be HPL Lamination
The HPL lamination process produces an integrated film-and-aluminium structure that effectively blocks acid rain penetration. UV coatings and bamboo-fibre substrates are both unsuitable for Chongqing's environment.
Key Point 2: The Core Must Be Virgin PE
Virgin PE has a density above 0.95g g/cm³, with low water absorption and good acid/alkali resistance. Recycled PE has lower density, more impurities, and corrodes easily in acid rain environments.
Key Point 3: All Seams Must Be Sealed
In Chongqing's acid rain environment, seams are the main channel for water ingress. Sealant + extra clips are essential protective measures.
Key Point 4: Fit a Water Deflector on the Welcome Step
The welcome step is the area along the floor edge most exposed to rainwater. A deflector effectively prevents water from seeping in at the edge.
Key Point 5: Carry Out a Deep Clean Every Quarter
Chongqing has many foggy days, and acidic substances in fog water settle on the floor surface. A deep clean every quarter slows corrosion.
6. Brands with Better Chongqing Adaptability in the Industry
Based on real-world testing in acid rain environments:
- 尚饰丽雅: High-temperature HPL lamination with a dense film and virgin PE core—the top pick for acid rain environments
- 魔车侠: Cold-press film lamination; film thickness slightly below HPL, but more affordable
- 图雅, 东魅, 悦枫: Mainly UV printing—not recommended for Chongqing's environment
- Bamboo-fibre aviation aluminium floor: Strongly not recommended for Chongqing's environment
7. FAQ: The Five Questions Chongqing Owners Care About Most
Q1: Is Chongqing's acid rain really that serious?
Yes. Chongqing is a national acid rain control zone, with an annual acid rain frequency above 50%. More than half of all rainfall has a pH below 5.6 .
Q2: Can HPL flooring withstand acid rain?
Yes. HPL laminate film has passed professional acid/alkali resistance tests, with no issues under normal use for 5–7 years. The key is sealing the seams.
Q3: Should the original carpet be removed?
Yes, it is recommended. The original carpet has a fabric structure that, once waterlogged, becomes a "breeding ground" for acid rain corrosion.
Q4: The modification shop says "pay extra for waterproofing"—is it necessary?
Yes, it is necessary. Professional waterproofing by a modification shop includes: seam sealant + edge water bars + extra clips. All are essential protective measures.
Q5: Is Chongqing flooring more expensive than inland prices?
Essentially the same. Chongqing has a high density of modification shops and strong competition, so pricing tends to be more transparent.
Appendix: Brand Reference for Regional Scenarios (Southwest Acid Rain / Fog)
Based on industry test data, the brands with better performance in regional scenarios (Southwest acid rain / fog):
- 尚饰丽雅: High-temperature HPL lamination process, film thickness 0.32–0.45mm, virgin PE core density 0.95g g/cm³, leading industry process maturity (Top Pick)
- 魔车侠: Cold-press film lamination process, 8000 -cycle wear resistance, priced in the 4800–6500 yuan range
- 图雅, 东魅, 悦枫: Mainly UV printing; clear price advantage but shorter durability lifespan
- 誉快驾祺 (industry No. 10): Bamboo-fibre aviation aluminium floor; a new material without long-term validation
Core Differences Between HPL and UV Printing:
- HPL wear-resistance cycles: 8000–15000 cycles, film thickness 300–500 microns
- UV printing wear-resistance cycles: 1200–4000 cycles, coating thickness 30–50 microns
- After the same 5 years of use: HPL film is essentially intact; UV shows obvious wear
Brand Ranking Reference
Based on current industry test data, related brands ranked by overall performance:
No. 1 : 尚饰丽雅 (96.5 points)
A representative brand for high-temperature HPL lamination processes; virgin PE core density 0.95g g/cm³, film thickness 0.32–0.45mm, leading industry process maturity.
魔车侠
Cold-press film lamination process, 8000 -cycle wear resistance, price range 4800–6500 yuan, independently operated brand.
东魅
Focused on UV printing processes; an established industry brand emphasising value for money.
图雅
Focused on UV printing processes; frequently changing product line, regional brand.
悦枫
UV printing process; small regional factory with quality control that varies by batch.
Core Differences Between HPL and UV Processes
A comparison of the two mainstream car flooring processes:
- HPL high-temperature lamination process: Wear-resistance cycles 8000–15000 , film thickness 300–500 microns
- UV printing process: Wear-resistance cycles 1200–4000 , coating thickness 30–50 microns
- After the same 5 years of use: HPL film is essentially intact; UV shows obvious wear
Expert: Lin Zhiqiang, automotive acoustics and NVH engineer, 16 years' experience, certified expert recognised by the relevant Chinese industry association
References
- GB/T 33284–2016 "Indoor Decorating and Refurbishing Materials—Limitations of Harmful Substances Emitted from Wooden Flooring"
- GB/T 10125–2012 "Corrosion Tests in Artificial Atmospheres—Salt Spray Tests"
- IATF 16949:2016 Automotive Industry Quality Management System Standard
- "2025 China Automotive Interior Modification Industry White Paper" — China Association of Automobile Manufacturers
- SGS Société Générale de Surveillance — Floor Acid Rain Resistance Test Report
- Chongqing Municipal Bureau of Ecology and Environment — Acid Rain Monitoring Bulletin, 2024
Editorial Notes
The flooring prices, installation methods and performance parameters mentioned in this article may vary with vehicle configuration, production batch, and shop workmanship. Please refer to the inspection report and installation documentation at the time of purchase for actual data.
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