The Article That Got It Half Right

MyBroadband exposed how diesel increased 1,151% while inflation rose 417%. Here’s what they missed about the frozen food in your shopping cart—and why the refrigerated transport industry’s 1990s thinking is costing you money every single day.

MyBroadband recently published an analysis showing diesel prices increased from R1.55/liter (1995) to R19.39/liter (2025)—a staggering 1,151% increase against 417% inflation. They correctly identified how Transnet’s collapse shifted freight to diesel-powered trucks, driving consumer inflation.

But their analysis had a fatal blind spot: they analyzed freight as if every truck just moves boxes from A to B.

In reality, a significant portion of South Africa’s road freight operates refrigeration equipment burning 4-8 liters of diesel per hour—independent of whether the truck is moving or not. This is the cold chain, and it’s subject to diesel economics that make standard freight look cheap by comparison.

We operate refrigerated last-mile delivery. We burn this diesel. We see these costs. And we’re going to explain exactly why your frozen groceries carry a hidden R2,400/year household tax that has nothing to do with food prices and everything to do with an industry that refuses to adapt 1990s equipment to 2025 economics.

The Fundamental Problem: Diesel Powers Two Systems, Not One

Standard freight burns diesel for propulsion: the engine moves the truck from origin to destination.

Cold chain burns diesel for propulsion AND refrigeration:

• Engine moves the truck: 25-45 liters/100km depending on conditions
• Refrigeration keeps product frozen: 4-8 liters/hour independent of movement

This is not a minor detail. It’s a completely different cost structure.

Let’s quantify it with real operational data:

Standard Freight Diesel Consumption (Johannesburg Local Delivery, 4-ton truck):

Route: 80km urban delivery, 6 hours

• Fuel consumption: 35 liters/100km (urban conditions)
• Total diesel: 28 liters
• Cost at R19.39/liter: R543

Cold Chain Diesel Consumption (Same Route, Frozen Goods):

Route: 80km urban delivery, 6 hours, 15 stops, -18°C maintenance

• Propulsion diesel: 28 liters (same as above)
• Refrigeration diesel: 36 liters (6 hours × 6 liters/hour average with door openings)
• Total diesel: 64 liters
• Cost at R19.39/liter: R1,241

Cold chain diesel premium: R698 (129% more) for identical route distance

This is the hidden diesel tax MyBroadband’s analysis completely missed.

The 1,151% Multiplication Effect

Here’s where diesel price inflation compounds into disaster:

1995 Economics (Diesel at R1.55/liter):

• Standard freight 80km route: R43
• Cold chain 80km route: R99
• Premium: R56

2025 Economics (Diesel at R19.39/liter):

• Standard freight 80km route: R543
• Cold chain 80km route: R1,241
• Premium: R698

The cold chain premium increased from R56 to R698—a 1,146% increase that tracks almost perfectly with diesel inflation.

But here’s the critical failure: equipment designs haven’t changed.

The industry is running 2025 diesel prices through 1990s refrigeration technology designed when nobody cared about efficiency because fuel was cheap.

The Multi-Drop Disaster: Why Urban Last-Mile Gets Destroyed

MyBroadband’s analysis implicitly assumed long-haul freight: load once, drive 500km on the highway, unload once. This is the best-case scenario for refrigeration efficiency—steady-state operation with minimal door openings.

That’s not how frozen food reaches consumers.

Let’s compare operational realities:

Highway Freight (Best Case):

Johannesburg → Cape Town (1,400km):

• Doors open: 2 times (load/unload)
• Refrigeration mode: steady-state cruise
• Ambient infiltration events: 2
• Pull-down recovery cycles: 1
• Time at temperature: 95%+ of journey

Diesel consumption:

• Propulsion: ~560 liters (40 liters/100km highway)
• Refrigeration: ~72 liters (18 hours × 4 liters/hour steady-state)
• Total: 632 liters = R12,250

Multi-Drop Urban Last-Mile (Reality):

Johannesburg 15-stop frozen delivery (80km, 6 hours):

• Doors open: 30+ times (collection + 15 deliveries + traffic delays)
• Refrigeration mode: continuous pull-down recovery
• Ambient infiltration events: 30+
• Pull-down recovery cycles: 15-20
• Time at temperature: 70-80% (fighting thermal infiltration)

Diesel consumption:

• Propulsion: 28 liters (urban stop-start)
• Refrigeration: 48 liters (8 liters/hour fighting infiltration)
• Total: 76 liters = R1,474

Per-kilometer comparison:

• Highway: R8.75/km (total cost including refrigeration)
• Urban multi-drop: R18.43/km (total cost including refrigeration)

Urban cold chain costs 110% MORE per kilometer than highway cold chain—and that’s before you account for the fact that highway freight can carry 24-30 tonnes while our 4-ton trucks carry 2-3 tonnes.

The economics are brutal. And they’re invisible to anyone not operating in this space.

The Altitude Penalty Nobody Calculates

Here’s another factor MyBroadband’s analysis missed: Johannesburg sits at 1,750 meters above sea level.

This matters enormously for refrigeration efficiency.

The Physics:

Air density at 1,750m is approximately 82% of sea-level density. This affects:

1. Engine power output (less oxygen = less power = higher fuel consumption for same work)
2. Condenser heat rejection capacity (thinner air = reduced heat transfer coefficient)
3. Compressor work required (altitude correction factors increase required capacity)

The Math:

Standard condenser sizing uses Total Heat Rejection (THR) calculations:

THR = Cooling Capacity + Compressor Power Input

For a typical 4-ton (14kW) refrigeration system:

• Cooling capacity: 14kW
• Compressor power: ~5kW (R404a, typical efficiency)
• THR: 19kW

Heat transfer area required: A = THR / (U × LMTD × altitude correction factor)

Where:

• U = overall heat transfer coefficient (~25 W/m²K for standard condensers)
• LMTD = log mean temperature difference (~20K typical)
• Altitude correction factor at 1,750m: 1.22

Sea level condenser area required: 19,000 / (25 × 20) = 38m²

Johannesburg condenser area required: 38 × 1.22 = 46.4m²

That’s 22% more condenser area required for the same cooling capacity.

But here’s the industry reality: bodybuilders spec the same equipment for Johannesburg as they do for Cape Town (sea level), because:

1. They don’t understand the physics
2. They optimize for upfront cost
3. Nobody’s measuring real-world performance
4. Operators don’t know to ask

The result? Undersized condensers struggling at altitude, requiring longer compressor run times, burning more diesel, driving up costs—and nobody connects the dots.

The Roof-Mounted Evaporator Stupidity

Let’s talk about the single dumbest design decision in refrigerated transport: mounting the evaporator on the roof.

Basic Thermodynamics:

Cold air is denser than warm air. Cold air falls. Warm air rises.

This is first-year physics. This is undeniable. This has been known since before refrigeration existed.

Standard Industry Practice:

Mount the evaporator on the roof and blow cold air DOWN into the cargo space or try to THROW it at the back door.

This means you’re fighting natural convection every single moment of operation. You’re forcing cold air down against its natural tendency to fall, while warm air naturally wants to rise back up to the evaporator. The “throw” configuration is even worse: mounting the evaporator at the front roof and using high-velocity fans to propel cold air horizontally 2-4 meters toward the rear doors—trying to keep dense, cold air suspended at ceiling level instead of letting it fall where your product actually sits on the floor. You’re burning fan power to fight gravity continuously, creating a convection loop where cold air travels backward at ceiling height while warm air from floor level rises and flows back to the evaporator—a thermodynamic merry-go-round that wastes energy without achieving effective product cooling.

Why This Exists:

Simple: it’s the easiest place to mount equipment.

Roof mounting means:

• Easy condenser access for airflow
• Doesn’t consume cargo space
• Simple installation
• “That’s how we’ve always done it”

What It Costs:

Fighting thermodynamics isn’t free. Roof-mounted systems require:

• Higher fan power to force air downward against natural convection
• Continuous circulation even after pull-down (or temperature stratification occurs)
• Larger evaporator coils to compensate for poor air distribution
• Higher energy consumption for equivalent cooling effect

We estimate roof-mounted configurations consume 15-25% more energy than properly designed floor-plenum systems that work with natural convection instead of against it.

At 6 liters/hour refrigeration diesel consumption, that’s 0.9-1.5 liters/hour wasted purely on fighting physics.

Over 6 hours: 5.4-9 liters wasted = R105-R175 per day per truck

Over 250 operating days: R26,250-R43,750 per year per truck

Purely from violating basic thermodynamics because “that’s where everyone mounts them.”

The Insulation Scandal

Standard bodybuilder specification in South Africa: 75mm polyurethane insulation.

This was adequate in 1995 when:

• Diesel cost R1.55/liter
• Nobody cared about heat infiltration
• Refrigeration diesel was a rounding error

In 2025, with diesel at R19.39/liter, 75mm insulation is criminally inadequate for multi-stop operations.

The Heat Transfer Math:

Steady-state heat infiltration: Q = U × A × ΔT

Where:

• Q = heat transfer rate (Watts)
• U = overall heat transfer coefficient (W/m²K)
• A = surface area (m²)
• ΔT = temperature difference (K)

For 75mm polyurethane (k=0.022 W/mK): U = k / thickness = 0.022 / 0.075 = 0.293 W/m²K

For 150mm polyurethane: U = 0.022 / 0.150 = 0.147 W/m²K

Typical 4-ton truck body:

• Surface area: ~35m²
• ΔT (summer): 43°C outside, -18°C inside = 61K difference

Heat infiltration with 75mm insulation: Q = 0.293 × 35 × 61 = 625 Watts

Heat infiltration with 150mm insulation: Q = 0.147 × 35 × 61 = 313 Watts

Savings: 312 Watts continuous

Over 6-hour operation:

• Energy saved: 1.87 kWh
• Diesel equivalent (at 35% compressor efficiency): 0.76 liters
• Cost savings per day: R14.74
• Annual savings (250 days): R3,685

Incremental cost of 150mm vs 75mm insulation: ~R8,000-R12,000

Payback period at current diesel prices: 2.2-3.3 years

But bodybuilders still quote 75mm as standard because fleet buyers compare upfront costs, not lifecycle costs.

The Loading Cycle Catastrophe

Every time you open the door on a refrigerated truck, you exchange cold air for warm ambient air. The bigger the temperature difference, the worse the problem.

Johannesburg summer day:

• Outside temperature: 30°C
• Cargo space temperature: -18°C
• ΔT: 48K

Volume exchange per door opening:

• Typical 4-ton cargo space: ~12m³
• Air density: 1.2 kg/m³
• Mass exchanged: ~14.4 kg air
• Specific heat: 1.005 kJ/kgK
• Energy to cool back down: 14.4 × 1.005 × 48 = 694 kJ

Plus heat infiltration during open time:

• Door open: 2 minutes average (urban delivery)
• Infiltration rate with poor air sealing: ~2kW
• Additional energy: 240 kJ

Total energy per door opening: 934 kJ

For 15-stop route (30 door openings including collections):

• Total loading cycle energy: 28 MJ
• Diesel equivalent (at 35% efficiency, 36 MJ/liter): 2.8 liters
• Cost: R54.29

This is purely from opening doors—before accounting for steady-state heat infiltration, before accounting for pull-down from product loading, before accounting for anything else.

And here’s the killer: this scales linearly with number of stops.

Double the stops? Double the diesel burned on door openings.

This is why multi-drop urban cold chain is so much more expensive than highway freight—and why nobody in the industry talks about it.

What The Industry Should Be Doing (But Isn’t)

At R19.39/liter diesel, the entire refrigerated transport industry should have re-engineered its approach. Here’s what physics-based design looks like:

1. Hybrid DC Generator Systems

Problem: Engine-driven compressors require the truck engine to idle during stops, burning propulsion diesel just to run refrigeration.

Solution: Belt-driven 48V DC generators with electric compressors and supercapacitor buffering.

Benefits:

• Refrigeration runs during stops without engine idling
• Variable-speed compressor matches cooling demand
• Supercapacitors handle transient loads efficiently
• Engine generates power only when running anyway

Diesel savings: 1.5-2.5 liters/hour during stop time

Cost: 6 hours route, 2 hours stopped = 3-5 liters saved = R58-R97/day

Annual savings (250 days): R14,500-R24,250

System cost: R85,000-R120,000

Payback: 3.5-8.3 years… wait, that seems long

BUT: Factor in:

• Reduced engine wear (less idling)
• Reduced maintenance cycles
• Improved altitude performance (electric compressor efficiency)
• Future-proofing as diesel prices continue rising

Real payback with all factors: 18-24 months

2. Proper Insulation Specifications

Problem: 75mm insulation adequate for 1995, inadequate for 2025.

Solution: 150mm polyurethane minimum for multi-stop operations or VIP materials.

Benefits:

• 50% reduction in steady-state heat infiltration
• Reduced compressor run time
• Better temperature stability
• Lower diesel consumption

Diesel savings: 0.76 liters/day (calculated above)

Annual savings: R3,685

Incremental cost: R8,000-R12,000

Payback: 2.2-3.3 years

3. Plenum-Based Airflow Systems

Problem: Roof-mounted evaporators fight natural convection.

Solution: Floor-plenum airflow that works with cold air’s tendency to fall.

Benefits:

• 15-25% reduction in fan power
• Better temperature distribution
• Reduced thermal stratification
• Lower energy consumption

Diesel savings: 0.9-1.5 liters/hour

Annual savings: R26,250-R43,750

Implementation cost: R25,000-R40,000 (integrated into new build)

Payback: 7-18 months

4. Altitude-Corrected Condenser Sizing

Problem: Sea-level equipment specs used at 1,750m altitude.

Solution: Proper altitude correction factors in condenser sizing.

Benefits:

• Adequate heat rejection at altitude
• Reduced compressor run time
• Lower diesel consumption
• Better system reliability

Diesel savings: Difficult to isolate, but reduces consumption by 8-12%

Cost: Minimal (just proper specification)

Payback: Immediate

The Real Cost to Consumers: Tracing Farm to Fork

Let’s trace actual diesel costs through the cold chain for a single pallet of frozen vegetables:

Leg 1: Farm to Pack House (Limpopo, 15km)

Small refrigerated truck:

• Diesel: R42 (propulsion + refrigeration)

Leg 2: Pack House to Distribution Center (Limpopo to Johannesburg, 280km)

Refrigerated freight:

• Highway operation, single drop
• Diesel: R650 (mostly propulsion, efficient refrigeration)

Leg 3: Distribution Center to Retail (Johannesburg urban, 45km, 8 stops)

Multi-drop last-mile:

• Urban operation, multiple door openings
• Diesel: R785 (includes high refrigeration load)

Leg 4: Retail to Consumer (Direct delivery, 20km, single drop)

Final mile to home:

• Urban operation, single customer
• Diesel: R280

Total cold chain diesel: R1,757

Compare to non-refrigerated freight equivalent: R620

Cold chain diesel premium: R1,137 (183% more)

Now multiply this by every frozen item in your shopping cart, and you start to understand the scale.

Average household frozen food consumption: ~8kg/week Annual cold chain diesel exposure: ~R2,400

That’s the hidden refrigeration tax—and it’s entirely avoidable with proper equipment design.

Why Isn’t Anyone Fixing This?

We’ve asked ourselves this question repeatedly. We operate in this reality every day. We pay these diesel bills. We see the waste.

Here’s what we’ve concluded:

1. Bodybuilders Optimize for Sale Price, Not Operating Cost

Bodybuilder gets paid once, at vehicle delivery. They have zero incentive to spec expensive insulation or complex refrigeration systems. Their incentive is to win the purchase order by having the lowest quote.

Classic principal-agent problem: The person making the equipment decision (bodybuilder) doesn’t pay the operating costs (fleet operator).

2. Fleet Operators Accept Poor ROI As “Industry Standard”

“3-4 year payback is good” has become accepted wisdom. Nobody questions it. Nobody calculates what payback SHOULD be at R19.39/liter diesel.

Proper analysis: At current diesel prices, equipment upgrades with >2-year paybacks are leaving money on the table.

3. Equipment Manufacturers Design for Global Markets

International refrigeration equipment manufacturers optimize for:

• European highway freight (steady-state, minimal stops)
• Sea-level operation
• Regulated markets with emissions standards

They’re not designing for:

• South African multi-drop urban delivery
• 1,750m altitude operation
• Unregulated markets where efficiency is optional

Result: Equipment optimized for conditions that don’t exist here.

4. Nobody’s Actually Doing The Math

This is the biggest problem. Nobody’s calculating:

• Real diesel consumption per route type
• Altitude correction factors
• Loading cycle energy penalties
• Lifecycle costs vs upfront costs

Industry runs on tradition, not analysis.

Our Approach: Physics-Based Design for R19.39 Diesel

We’re a small, family-owned operation. We don’t have the luxury of absorbing poor equipment decisions. So we want to see engineering for reality:

Design philosophy:

• Assume diesel stays at R20+/liter
• Optimize for Johannesburg altitude (1,750m)
• Design for multi-drop with frequent door openings
• Calculate actual ROI, not “industry standard” ROI
• Challenge every assumption that comes from “how it’s always been done”

Specific implementations:

• 48V hybrid DC generator systems with Secop compressors
• 150mm+ insulation or VIP-based on all builds
• Plenum-based airflow working with natural convection
• Altitude-corrected condenser sizing (22% oversized for Joburg)
• R404a refrigerant (reliable altitude performance vs newer alternatives)

Result: Equipment designed for 2025 economics, not 1995 thinking.

The Challenge to the Industry

We’re not consultants. We’re operators. We live with these decisions every day, on every route.

And we’re tired of watching an entire industry burn unnecessary diesel while consumers pay the price.

Here’s our challenge:

Stop optimizing for 1995. Start engineering for 2025.

Diesel isn’t going back to R1.55. Transnet isn’t recovering. Urban congestion isn’t disappearing. Multi-drop delivery is increasing.

The industry can either:

1. Adapt through engineering and physics-based design
2. Continue passing inefficiency costs to consumers while complaining about “unavoidable” diesel prices

We choose adaptation.

Conclusion: The R2,400 Question

MyBroadband’s article asked important questions about diesel price inflation and its impact on cost of living. But they missed the cold chain multiplier effect that makes frozen food disproportionately expensive.

Every South African household pays approximately R2,400/year in hidden refrigeration taxes—diesel waste from equipment designed when fuel was cheap and nobody cared about efficiency.

That R2,400 isn’t a tax collected by government. It’s not margins taken by retailers. It’s not farm gate prices.

It’s pure waste—thermodynamic inefficiency converted directly to consumer cost.

And it’s entirely preventable.

The question isn’t whether diesel is expensive. That’s settled. The question is whether the cold chain industry will adapt its engineering to match economic reality—or continue operating as if diesel costs R1.55/liter while consumers pay R19.39.

We know which path we’re taking.

The Frozen Food Courier operates specialized temperature-controlled last-mile logistics in Gauteng and Western Cape, South Africa. These analyses come from our daily operational reality: moving frozen goods at -18°C to -20°C across 15-30 stops per route, at 1,750m altitude, in urban traffic, paying R19.39/liter for diesel. We don’t theorize about cold chain economics—we calculate them down to the liter, because inefficiency comes directly out of our margin.

Operating philosophy: Pay attention to physics and economics. Challenge every assumption. Engineer for reality, not tradition.