Isuzu KB 350 V6 Fuel Consumption: What Drivers Can Expect in South Africa
The Isuzu KB 350 V6 has earned a reputation in South Africa as a strong, reliable bakkie with plenty of power, but that performance comes with relatively high fuel consumption compared to modern diesel and smaller petrol engines. This article looks at the available factual data on the Isuzu KB 350 V6 fuel consumption, using only credible, verifiable sources.
Isuzu KB 350 V6 engine overview
The KB 350 V6 (also badged as the Isuzu KB 350i V6 in some markets) is powered by a 3.5‑litre V6 petrol engine. Isuzu’s Australian-market equivalent, the Holden Rodeo / Isuzu ute RA series, used a closely related 3.5‑litre V6 petrol engine producing around 147 kW and 280–305 Nm, depending on specification. GM Authority notes for this V6 family (the Isuzu 6VE1 and related units) that it is a 3.5‑litre DOHC 24‑valve engine widely used in Isuzu light trucks and SUVs in the 2000s, with a focus on power rather than efficiency compared with modern downsized engines:
https://gmauthority.com/blog/gm/gm-engines/6ve1-engine
While exact South African KB 350 figures are not listed in global databases, this engine type and displacement are consistent with higher petrol consumption than contemporary diesel bakkies of similar size.
Reported fuel consumption figures for the Isuzu KB 350 V6
Real‑world owner data (Australia – closely related model)
The clearest published fuel consumption data for the 3.5‑litre Isuzu V6 in a bakkie/ute application comes from Australia’s government-backed Green Vehicle Guide (GVG). Although this is for the Holden Rodeo 3.5‑litre V6 (RA series), it uses the same basic 3.5‑litre Isuzu V6 drivetrain layout as the KB 350 V6 sold in South Africa.
For the 2004 Holden Rodeo Crew Cab 3.5‑litre V6 petrol 4×4 manual, the GVG lists the following official test cycle figures:
– Urban: 17.5 L/100 km
– Extra-urban: 10.0 L/100 km
– Combined: 12.7 L/100 km
Source: Australian Government Green Vehicle Guide, 2004 Holden Rodeo V6:
https://www.greenvehicleguide.gov.au/Vehicle/Comparison?series=RODEO&model=HOLDEN&year=2004
Other 3.5‑litre Rodeo/Isuzu ute variants in the same database show similar combined figures in the 12–14 L/100 km range depending on body style, transmission, and drivetrain:
https://www.greenvehicleguide.gov.au/Vehicle/Search?make=HOLDEN&model=RODEO&year=2004
Because these figures are from an official government test cycle, they provide a reliable benchmark for what a comparable Isuzu KB 350 V6 is likely to achieve under standardized conditions.
Typical real‑world consumption range
Real‑world driving in South Africa often produces higher consumption than laboratory or test-cycle numbers, due to traffic, load, accessories, and driving style. While there is limited formal test data published specifically for the South African KB 350 V6, the official Australian numbers above and owner-reported figures referenced in regional discussions align on a similar pattern:
- Light, steady highway driving: around 10–12 L/100 km is realistic for an unloaded vehicle driven conservatively (close to the extra-urban figure of 10.0 L/100 km from the GVG data above:
https://www.greenvehicleguide.gov.au/Vehicle/Comparison?series=RODEO&model=HOLDEN&year=2004 - Mixed urban/highway driving: many drivers can expect roughly 12–15 L/100 km, which brackets the combined 12.7 L/100 km rating reported for the similar V6 Rodeo/Isuzu ute.
- Heavy urban use and towing: it is reasonable, based on the 17.5 L/100 km urban test figure for the Rodeo V6, to see consumption creeping into the high‑teens per 100 km under stop‑start, heavily loaded, or high‑speed driving conditions:
https://www.greenvehicleguide.gov.au/Vehicle/Comparison?series=RODEO&model=HOLDEN&year=2004
These patterns are typical of larger petrol V6 engines in medium-size pickups from the early–mid 2000s era and are consistent with independent fuel economy reviews of similar class vehicles globally, such as EPA data for comparable petrol V6 pickups in North America:
https://www.fueleconomy.gov
How the KB 350 V6 compares with diesel bakkies
Modern Isuzu D‑MAX and other diesel double cabs commonly achieve combined-cycle figures between roughly 7–9 L/100 km according to manufacturer data and independent test bodies. For example, Isuzu’s 3.0‑litre turbo‑diesel D‑MAX models sold in markets like the UK and Australia are typically officially rated between about 7.0 and 8.0 L/100 km on combined cycles:
– Australian (ADR) ratings via the Green Vehicle Guide:
https://www.greenvehicleguide.gov.au/Vehicle/Search?make=ISUZU%20UTE&model=D-MAX
This means the KB 350 V6 petrol can use roughly 40–70% more fuel than an equivalent modern diesel Isuzu double cab in similar conditions. The trade‑off is a smoother petrol power delivery and strong performance from the V6, but with significantly higher running costs at the pump.
Factors that influence Isuzu KB 350 V6 fuel consumption
Even within the same model and engine type, fuel consumption can vary widely. The following well‑documented factors are known to affect fuel economy across vehicles and are discussed in resources such as the US Department of Energy’s fuel economy guidance:
https://www.energy.gov/eere/f vehicles/fuel-economy
Key influences include:
- Driving style
Aggressive acceleration, high sustained speeds, and hard braking increase fuel use in any vehicle. The Department of Energy notes that rapid acceleration and braking can lower fuel economy by 15–30% on highways and 10–40% in stop‑and‑go traffic:
https://www.fueleconomy.gov/feg/driveHabits.jsp -
Vehicle load and towing
Carrying heavy loads or towing trailers increases aerodynamic drag and rolling resistance, which can be especially noticeable in a petrol V6 bakkie. The US DOE explains that every additional 45 kg (100 lb) can reduce fuel economy, particularly in smaller vehicles, though larger utes are also affected:
https://www.fueleconomy.gov/feg/weight.shtml -
Tyre pressure and tyres
Under‑inflated tyres increase rolling resistance and therefore fuel consumption. The US National Highway Traffic Safety Administration highlights that properly inflated tyres can improve fuel economy by around 3%:
https://www.nhtsa.gov/equipment/tires -
Aerodynamic add‑ons
Roof racks, canopies with poor airflow design, and other accessories can increase drag. The US Department of Energy notes that external cargo and racks, especially at higher speeds, can significantly reduce fuel economy:
https://www.fueleconomy.gov/feg/cargoracks.shtml -
Maintenance
Worn spark plugs, clogged air filters on older vehicles, incorrect engine oil viscosity, and poor general maintenance all affect fuel consumption. The DOE details how keeping the engine properly tuned and maintaining the emissions system can improve fuel economy:
https://www.fueleconomy.gov/feg/maintain.jsp
Practical tips to reduce fuel consumption in a KB 350 V6
While a 3.5‑litre petrol V6 will never match modern diesels in efficiency, careful driving and maintenance can keep consumption closer to the lower end of the expected range. The following tips are consistent with best-practice guidance from the sources above, such as FuelEconomy.gov and the US Department of Energy:
https://www.fueleconomy.gov
- Drive smoothly and keep speeds moderate
- Avoid rapid acceleration and heavy braking.
- On open roads, keep cruising speeds legal and steady – fuel consumption rises significantly at high speeds due to aerodynamic drag.
- Plan trips and avoid unnecessary idling
- Combine journeys to reduce cold starts.
- Avoid long periods of idling where safe and legal; idling gets 0 km per litre.
- Check tyre pressures regularly
- Inflate tyres to the recommended pressures listed in the vehicle’s door-jamb sticker or owner’s manual. Under‑inflated tyres can add several percent to fuel use.
- Limit unnecessary weight and drag
- Remove heavy items from the load bin when not needed.
- Take off unused roof racks or carriers to reduce aerodynamic drag on highways.
- Maintain the engine properly
- Follow recommended service intervals for oil, filters, and spark plugs.
- Address any engine warning lights or performance issues promptly.
- Choose the right tyres and accessories
- Aggressive off-road tyres can increase rolling resistance compared with highway‑terrain tyres.
- When fitting a canopy, consider more aerodynamic designs if you do lots of highway driving.
Summary: Isuzu KB 350 V6 fuel consumption in context
Drawing on official test data for the closely related 3.5‑litre Isuzu V6 ute/ pickup as published by the Australian Government’s Green Vehicle Guide, realistic expectations for the Isuzu KB 350 V6 in South African conditions are:
- Around 10–12 L/100 km on open highways when driven gently and lightly loaded (similar to the extra-urban figure of 10.0 L/100 km reported for the 3.5‑litre Holden Rodeo V6:
https://www.greenvehicleguide.gov.au/Vehicle/Comparison?series=RODEO&model=HOLDEN&year=2004) - Around 12–15 L/100 km in mixed real‑world daily use, which brackets the official combined 12.7 L/100 km rating for that comparable V6 ute.
- Potentially 17 L/100 km or more in heavy stop‑start urban driving, when towing, or when driven aggressively – consistent with the 17.5 L/100 km urban figure shown for the Rodeo V6 in the Australian test cycle:
https://www.greenvehicleguide.gov.au/Vehicle/Comparison?series=RODEO&model=HOLDEN&year=2004
While the Isuzu KB 350 V6 is thirsty compared with modern diesel double cabs, many owners value its strong petrol performance and reliability. By understanding how driving habits, load, and maintenance affect fuel use – as outlined in efficiency guidance from FuelEconomy.gov and the US Department of Energy:
https://www.fueleconomy.gov/feg/drive.shtml
drivers can better manage their running costs and get the most from this powerful Isuzu bakkie.