MG ZS Hybrid Software Update Review: Did It Fix Power Issues?

content: The Critical Hybrid Flaw That Needed Fixing

Imagine accelerating to merge onto a highway, only to discover your SUV delivers just 30kW instead of its promised 158kW. This was the terrifying reality for early MG ZS Hybrid Plus owners. When the hybrid battery depleted to 10%—far lower than Toyota or Hyundai systems that maintain ~40% charge—drivers faced dangerous power deficits during overtakes or hill climbs. After our initial 2023 review highlighted this critical safety flaw, MG released a software update promising solutions. Having tested the updated model extensively, I can confirm: improvements exist, but significant compromises remain.

How MG's Hybrid System Failed Drivers

The core issue stemmed from MG's aggressive battery depletion strategy. Unlike competitors, the ZS Hybrid prioritizes electric propulsion, relying on a potent 100kW electric motor (supported by a 75kW petrol engine). When the battery drained below 10%, the electric motor couldn't deliver peak output. As Drive's Alex noted: "Put your foot down, and it feels like the car is stuck in neutral." This wasn't mere inconvenience—it created legitimate safety risks during highway merges or passing maneuvers. The system's design amplified the problem: since 70% of the powertrain's combined 158kW relies on electricity, battery depletion crippled performance more severely than in engine-dominated hybrids.

MG's Software Fix: What Changed Under the Hood

MG's December 2023 update introduced three key recalibrations:

1. Active Battery Charging Under Load: The engine now charges the battery when detecting heavy acceleration or inclines, maintaining a "moderate state of charge."
2. Engine Engagement on Inclines: At moderate speeds uphill, the petrol engine activates earlier to preserve battery reserves.
3. High-Speed Power Assurance: Above 100km/h, the engine runs continuously to prevent power loss, regardless of battery level.

Real-World Testing: Improvements and Limitations

During our hill tests, the update demonstrated tangible benefits. The battery rarely dropped below 3 bars (vs. 1-2 bars pre-update), and minimum power output during hard acceleration increased to 50-60kW—double the original 30kW failure state. However, our testing revealed unresolved issues:

• Battery Depletion Still Occurs: During sustained highway climbs without braking opportunities, charge levels still plummet, triggering power reduction.
• Increased Engine Noise: To maintain charge, the engine frequently revs to 3,000-4,000 RPM during cruising. Colleagues remarked it sounded "like it's stuck in first gear"—a notable refinement downgrade.
• Fuel Economy Trade-Off: While MG's 4.7L/100km claim remains unchanged, real-world consumption rose to ~6.0L/100km (vs. 5.3L pre-update). Competitors like the Toyota Corolla Cross Hybrid (≈4.0L/100km) retain efficiency advantages.

Living With the Updated ZS Hybrid: Practical Realities

Beyond the powertrain, the ZS Hybrid excels as a value-focused family SUV. The Excite trim ($33,990 drive-away) includes a 12.3-inch touchscreen with wireless Apple CarPlay, 360-degree camera, and MG's standout 10-year/250,000km warranty—valid even with independent servicing.

Cabin and Practicality Highlights

• Spacious Rear Seats: At 186cm (6'1"), I fit comfortably behind my own driving position with ample knee/headroom.
• Competitive 443L Boot: Features adjustable floor height, bag hooks, and side nets (though lacks a spare wheel—common among hybrids).
• User-Friendly Tech: Climate controls via touchscreen require acclimatization, but physical buttons for drive modes remain.

Lingering Hybrid Quirks

The 3-speed automatic transmission contributes to the engine's vocal behavior during charging. Power delivery remains nonlinear compared to Toyota's e-CVT or Hyundai's 6-speed hybrid systems. While handling is composed, steering feels heavy on winding roads—a reminder this prioritizes affordability over dynamism.

Verdict: Progress Made, But Not Perfected

MG deserves credit for addressing a critical flaw through a no-cost software update—a responsiveness uncommon in the industry. The changes reduce low-battery power loss incidents, making the ZS Hybrid safer. However, our testing confirms:

• Power deficits still occur under specific conditions
• Refinement suffers from frequent high-RPM engine operation
• Efficiency lags rivals despite improvements

Should You Buy It? A Balanced Checklist

Consider the ZS Hybrid Plus if you:
✅ Prioritize upfront value over long-term efficiency
✅ Accept occasional powertrain quirks for $10k+ savings vs rivals
✅ Value industry-leading warranty flexibility

Look elsewhere if you:
❌ Frequently drive steep, sustained inclines
❌ Demand Toyota-level hybrid refinement
❌ Require class-leading fuel economy

"The update makes the ZS Hybrid less flawed, but not class-competitive," concludes our testing team. For urban drivers seeking budget-friendly efficiency, it's now viable. For those tackling hills daily or prioritizing silence, a Corolla Cross Hybrid remains superior—despite its higher price.

Your Experience Matters: Have you test-driven the updated ZS Hybrid? Share whether the engine noise or power delivery would be a dealbreaker for your daily commute in the comments.