LPG vs Diesel Generator for Mobile Catering: Which Should You Buy?
Last updated: June 2026
In 30 seconds:
- For most UK food trailers, an LPG generator beats diesel — quieter, cleaner, and it runs on the propane you already carry.
- LPG: Greengear from £649 (3 kW) to £1,249 (7 kW). Diesel: Warrior from £1,299 (6.25 kVA).
- Diesel suits heavy setups — 8 kW+ demand, long unattended runs, big multi-day events.
- Since April 2022, caterers typically can’t run cheap red diesel. You pay pump prices.
Not sure what size you need first? Try our LPG generator sizing calculator. It takes two minutes and saves you buying the wrong unit.
A dedicated LPG generator is the standard recommendation for UK mobile caterers who already cook on propane. It’s widely regarded as the simpler, quieter choice for food vans and trailers — one fuel on board, one supplier, no diesel cans in the same space as food.
Why LPG first? Your trailer almost certainly carries propane cylinders already. An LPG generator plugs into that same supply chain — no second fuel to store, no spills, no diesel smell drifting over your serving hatch.
When does diesel make sense? When the maths gets big. Diesel engines are workhorses for high continuous loads and very long runs. If you need 8 kW or more, or three-phase power, diesel earns its place.
The biggest mistake we see? Choosing the fuel before counting the appliance loads. Buyers fall for “diesel is cheaper to run”, lug a heavy, clattery set to a coffee pitch, and find the fuel rules changed in 2022 anyway. Count your watts first — the right fuel usually picks itself.
Quick verdict: LPG vs diesel at a glance
| LPG (Greengear) | Diesel (Warrior) | |
|---|---|---|
| Best for | Coffee trailers, food vans, market pitches, quiet events | Heavy loads (8 kW+), long unattended runs, big trailers |
| Price | from £649 (3 kW) · from £949 (5 kW) · from £1,249 (7 kW) | from £1,299 (6.25 kVA) |
| Fuel on board | Propane — the cylinders you already carry | White diesel — a second fuel to store and fetch |
| Noise | Smoother, softer engine note | Louder, clattery — needs distance or baffling |
| Exhaust | Clean burn, no fuel smell near food | Diesel fumes and smell to manage |
| Winter starting | Reliable — propane vaporises to −42°C; rated to −10°C ambient | Good, but cold mornings can need glow-plug patience |
| Weight | 49–96 kg across the range | Heavier — usually a two-person lift or wheel kit |
How we compared them
We sell both. MobCater stocks the dedicated-LPG Greengear range and Warrior diesel sets, so we’ve no reason to talk one fuel up over the other. The right answer is whatever keeps your pitch powered without wasted money.
Every figure below comes from the manufacturer manuals we hold on file, or from running these units in real mobile catering setups. Where we can’t verify a number, we say so rather than guess.
LPG generators — quiet, clean, built for trailer life
First, one thing the listings don’t make obvious. Most “LPG generators” online are dual-fuel — a petrol engine with an LPG kit added. Greengear is different: factory-built for propane from the ground up, never a kit. Cleaner burn, smoother running, longer engine life under daily trading.
The mid-range GE-5000UK is the one most food vans end up with, so here it is in numbers.
Quick specs — Greengear GE-5000UK
- Power: 5.0 kW rated · 5.5 kW peak
- Engine: GG4GN, 389 cc, single-cylinder OHV, electric start
- Fuel use: ~398 g of propane per kWh
- Weight: 93 kg — two-person lift or wheel it
- Voltage: 115/230 V dual output, 50 Hz
- Price: from £949 — view the GE-5000UK product page
Best for
Multi-appliance food vans — fryer, griddle, lights and ventilation running together. Busy coffee setups with electric water heating fit here too.
What it runs (all at once)
- A commercial fridge
- LED lighting and extraction fan
- Card terminal and till
- An electric griddle or soup kettle
- Phone chargers and a speaker
Total draw lands around 3–4 kW with headroom for motor surges. Fridges and pumps need 3–5 times their running watts to start — always size for the biggest surge, not just the total.
Don’t use it for
- Full electric cooking — twin fryers plus griddle plus bain marie will swamp it
- Anything needing three-phase supply
Trade-off
Output tops out at 7 kW in this range. The smaller GE-3000UK (from £649, 49 kg, one-person lift) suits coffee trailers; the GE-7000UK (from £1,249) handles full commercial fit-outs. Past that, you’re into diesel territory.
Diesel generators — raw stamina for heavy setups
Diesel sets are the long-distance runners. The engines are built for hours of steady, heavy load, and the fuel goes a long way per litre. For big trailers and multi-day events, that stamina is the whole appeal.
Quick specs — Warrior LDG6500SV diesel
- Power: 6.25 kVA single-phase
- Starting: Electric start
- Warranty: 2-year limited (manufacturer terms)
- Price: from £1,299 — view the Warrior diesel product page
Best for
High continuous loads, long unattended runs, and traders who already manage diesel for a vehicle or plant. Bigger Warrior and Gorilla Power sets in our diesel range go well past 10 kVA, including three-phase.
What it runs (all at once)
- Multiple refrigeration units
- Electric fryer or large griddle
- Full lighting, extraction and tills
- Heaters or hot cabinets in winter
Don’t use it for
- Small coffee or crepe pitches — it’s heavy, loud overkill
- Quiet residential markets or events with strict noise limits
Trade-off
Weight, noise and a second fuel. You’ll be storing diesel cans alongside food, managing the smell, and lifting a unit that usually needs two people. And the old running-cost advantage shrank when the red diesel rules changed.
Running costs in the real world
The red diesel rule changed in 2022. Since April 2022, mobile catering isn’t on HMRC’s allowed list for rebated red diesel. That means white diesel at pump prices for your generator — the cheap-fuel argument that sold a generation of diesel sets is mostly gone.
What LPG actually burns. The GE-5000UK uses roughly 398 g of propane per kWh. At a 2.5 kW average load over an 8-hour trading day, that’s about 8 kg of propane. A 47 kg cylinder gives you around six trading days at that pace.
Greengear quotes typical fuel savings of around 40% against petrol. Diesel engines are efficient too — per litre, diesel still stretches further than most fuels. But once you add pump-price diesel, a second fuel run, and extra servicing, the gap for a typical caterer narrows to very little.
Servicing. Greengear maintenance is owner-friendly: check oil daily, clean the air filter weekly, change oil every 100 hours. Diesel sets want regular fuel-filter and injector care on top of oil — more to do, or more to pay someone for.
Working out cylinder logistics? Our LPG cylinder sizes guide for mobile catering covers 19 kg vs 47 kg, run times and swap costs.
Noise, weight and where you’ll put it
Propane burns more smoothly than diesel, so an LPG set runs with a softer engine note. On a quiet market square or at a wedding pitch, that difference decides whether the organiser invites you back.
Weight matters more than buyers expect. The GE-3000UK is 49 kg — one person can load it. Most diesel sets of useful catering size need two people or a wheel kit, every single pitch.
One rule both fuels share: never run any generator inside the trailer or van. Exhaust contains carbon monoxide. Site it outside, away from the hatch, with the exhaust pointing away from people.
Which should you buy?
- Coffee trailer or low-draw pitch: Greengear GE-3000UK (from £649). Light, quiet, runs the machine-and-fridge setup all day.
- Multi-appliance food van: Greengear GE-5000UK (from £949). The sweet spot for fryer-plus-griddle-plus-lights builds.
- Hog roast, pizza or festival rig: Greengear GE-7000UK (from £1,249). Headroom for refrigeration surges and ventilation.
- 8 kW+, three-phase, or very long unattended runs: a Warrior or Gorilla Power diesel set. Accept the weight and noise; you’re buying stamina.
Planning the whole power-water-propane picture? Our off-grid mobile catering setup guide puts the generator decision in context.
Real-world example: the festival burger trailer
A typical 16 ft burger trailer cooks on propane — fryer, griddle and grill all run straight off the cylinders. The generator only needs to carry the fridge, lights, extraction and card machine. That’s about 2 kW continuous with a fridge surge on top.
A 3 kW dedicated LPG unit covers it from the same cylinder bank, with no diesel cans in the food space and no clatter over the serving hatch. Buying a 6 kVA diesel set for that job means paying more, lifting more, and listening to more — for power you never use.
Service, support, and why “dedicated LPG” matters
Most “LPG generators” sold cheap online are petrol generators with a conversion kit. They run on propane, but aren’t built for it — compromised carburetion, faster engine wear, weaker cold-start reliability.
Greengear is different — dedicated and purpose-built, never a kit, never dual-fuel. Every GE-series generator is factory-built for LPG/propane only from the ground up — single fuel, purpose-designed carburetion, optimised compression. Cleaner burn, quieter running, longer engine life, and the cold-start reliability you need on a frosty market morning.
What you get with us on every Greengear sale:
- Pre-purchase sizing advice. We work out continuous wattage AND peak surge load from your appliance list. Right model first time.
- Cylinder pairing. Which propane cylinder (19 kg portable vs 47 kg trailer-mount) suits your run time, and how to set the 37 mbar regulator correctly for UK appliances.
- UK-stocked spare parts. Air filters, spark plugs, recoil starters, oil — on the shelf, no waiting on imports.
- CP44 and gas safety guidance. We point you to qualified mobile engineers for commercial gas certification.
- Real-world troubleshooting. Talk to people who’ve actually run these in food trailers — not a call centre.
FAQs: LPG vs diesel generators for mobile catering
Is an LPG generator better than a diesel generator for a food trailer?
For most UK food trailers, yes. An LPG generator is quieter, burns cleaner, and runs on the propane you already store for cooking. Diesel only wins when you need very high output — around 8 kW or more — or very long unattended runs. Count your appliance loads first, then choose the fuel.
Are LPG generators quieter than diesel generators?
Generally, yes. LPG burns more smoothly than diesel, so the engine note is softer and less clattery at working load. That matters on quiet market pitches and at events with noise limits. Diesel sets usually need more distance or baffling to reach the same comfort level.
Can I run my catering generator on red diesel?
Typically no. Since the April 2022 rule change, mobile catering isn’t on HMRC’s allowed list for rebated red diesel, so you should run white diesel at pump prices. That change removed most of diesel’s old running-cost advantage for caterers comparing fuels today.
How long will a 47 kg propane cylinder run an LPG generator?
Around six 8-hour trading days on a 5 kW Greengear at a 2.5 kW average load. The manual quotes roughly 398 g of propane per kWh, which works out near 8 kg per day. Lighter loads stretch a cylinder considerably further.
Do LPG generators start in cold weather?
Yes. Propane vaporises down to about −42°C, and Greengear units are rated for ambient temperatures from −10°C to +40°C. Always pair the generator with propane, never butane — butane stops vaporising below about 2°C, which makes it useless for UK winter trading.
What size generator does a food van need?
Most food vans land between 3 kW and 7 kW. Add up the running watts of every appliance, then check the largest motor’s surge — fridges and pumps need 3–5 times their running wattage to start. Size for the biggest surge, not just the total.
Are diesel generators cheaper to run than LPG?
Not by much for caterers any more. Diesel engines are efficient, but you pay white-diesel pump prices since the 2022 red diesel rules changed. Greengear quotes typical propane savings of around 40% against petrol, and you already carry cylinders — one fuel, one supplier.
Does an LPG generator need a gas safety certificate?
The generator is fed from your propane cylinder, so its hose and regulator should be part of your gas-safety checks. Mobile caterers typically need an annual CP44 commercial gas certificate covering the whole LPG installation. A qualified mobile engineer can include the generator connection in the same visit.