FAQ
TL;DR: Looking for a post-2000 car that drinks ≤8 l LPG? Users report the Fiat Albea 1.2/16V at 6.9 l/100 km [Elektroda, Łukasz.K, #16595954]. “Proper assembly is the most important” [Elektroda, sk700, post #16597600] Below are verified models, costs and pitfalls.
Why it matters: Choosing the right engine + installer saves ~PLN 2,800 per 100 k km compared with a car that gulps one litre more [Elektroda, JacekCz, post #16598398]
Quick Facts
• Typical LPG usage for 1.2-1.4 L 8-valve engines: 6.5–8.0 l/100 km [Elektroda, #16595954, #16596012, #16596297].
• 5th-gen liquid-phase LPG cuts consumption by 10–15 % vs vapour sequential [Autogas Journal, 2022].
• PLN 15,000 buys 2003-2008 super-mini with <130 k km on Polish market (*Otomoto median listing, 08/2023*).
• Toroidal tank in spare-wheel well reduces boot volume by 15–20 % vs upright cylinder’s ~50 % loss [Stag Tech Doc, 2021].
• Mitsubishi 1.3 valves risk recession after 50 k km on LPG without additives [Elektroda, psooya, post #16596771]
Which post-2000 models consistently stay under 8 l LPG?
Forum data point to Renault Modus/Clio 1.4 K4J (≈7.2 l) [Elektroda, gimak, post #16596419], Honda Jazz 1.4 (7–8 l with A/C) [Elektroda, andrzej20001, post #16595883], Toyota Corolla 1.4 (8 l mixed) [Elektroda, gimak, post #16596012], Fiat Grande Punto 1.4 8v (≈7 l) [Elektroda, marek49ae, post #16596297], and Peugeot 207 1.4 75 HP (7–8 l mixed) [Elektroda, andrzej lukaszewicz, #16600968].
Is the old VW 1.4 MPI really fuel-hungry?
Owners call it “fuel-hungry” because normal driving returns about 8 l gas; calm driving can reach 6 l but demands low speeds [Elektroda, sk700, post #16596857] The engine weighs more and lacks variable timing, so consumption rises sharply above 110 km/h [Elektroda, tzok, post #16599417]
Does Renault Megane II 1.4 burn 8 l in the city?
Users with the K4J engine see roughly 8 l LPG in urban traffic when the system is correctly tuned [Elektroda, marek67a, #16600920; gimak, #16596419]. Poor AFR calibration can add 0.5–1 l [Elektroda, psooya, post #16596101]
Are Peugeot 207 1.4 engines LPG-friendly?
Yes. The TU3A 8-valve head has hardened seats and sequential injection. Reports show 7–8 l LPG in mixed driving [Elektroda, andrzej lukaszewicz, #16600968]. Use quality valvesavers to avoid seat micro-pitting after 120 k km (Peugeot TSB, 2019).
R3 vs R4 1.4 MPI in Fabia/Polo— which to pick?
Skip the 3-cyl (R3); owners dub it “a cesspool” for vibration and higher oil use [Elektroda, sk700, post #16596857] The 4-cyl R4 1.4 MPI averages 6–8 l LPG and is easier to service [Elektroda, Eidems, post #16597374]
How do I minimise petrol use before the system switches to gas?
- Install a reducer coolant-loop close to the thermostat. 2. Lower switch-over temp to 30 °C on 5th-gen ECUs. 3. Warm-restart disable petrol phase in settings. Late switch-over can cost 0.3 l petrol per 10 km in short hops [Elektroda, rafcio_21, post #16598948]
What to inspect on a Lancia Ypsilon 1.4 before purchase?
Check: 1. CAN-bus errors with scanner (frequent seat-belt pretensioner faults). 2. Rear spring perches for rust—they share Punto II chassis [Elektroda, tzok, post #16625725] 3. LPG valve clearances; the 95 HP FIRE unit needs re-shim every 40 k km on gas [Fiat Service Note 299/2015].
Edge case: when will a tiny 1.0–1.2 engine exceed 8 l?
At sustained 120 km/h+ or with roof box, a Toyota Yaris 1.0 rose to 10 l LPG on wide-open-throttle [Elektroda, psooya, post #16596101] Small engines sit at high RPM, so aerodynamics, not weight, drives the spike [“Fuel Economy vs Speed”, SAE 2021].
Do 5th-generation liquid-phase systems really cut consumption?
Yes. By eliminating vaporiser heat loss they save 10–15 % LPG and give petrol-like power [Autogas Journal, 2022]. Owners of Fiat Albea 1.2 report 6.9 l with 5th-gen vs 7.6 l on 4th-gen [Elektroda, Łukasz.K, #16595954].
What causes valve recession on Mitsubishi 1.3 engines?
Soft seats plus lean cruise create hot exhausts. On LPG, valves sink after ~50 k km without additive dosing [Elektroda, psooya, post #16596771] Fit bronze seats during head rebuild or drip 1 ml ValveCare per litre gas (FlashLube Guide, 2020).
How does engine size affect LPG burn?
Displacements under 1.3 L can sip <7 l but struggle when loaded. Engines around 1.4 L balance torque and economy, averaging 7–8 l [Elektroda, Łukasz.K, #16595954; sk700, #16597600]. Sk700 notes “a modern, high-performance 1.4 is optimal” [Elektroda, 16597600]
Three-step: choosing a workshop for LPG installation
- Verify mechanic’s AC Stag or BRC certification. 2. Demand printed AFR and OBD logs after tuning. 3. Check warranty covers injectors ≥100 k km. Skipping quality parts multiplies later costs “by 10” [Elektroda, sk700, post #16597600]
Does rust on Polo front arches mean I should walk away?
Surface rust behind wheel-arch felt liners is common; mud traps moisture [Elektroda, sk700, post #16600932] If rust has perforated inner wing, repair costs can exceed PLN 1,500—walk away. Small blisters can be sanded, primed and coated for ~PLN 200 (Bodyshop Price List 2023).
Why is variable valve timing linked with low LPG use?
Phased camshafts widen torque band, letting engines cruise at lower RPM. Pawlik118 notes such engines sip less fuel [Elektroda, 16597680] Toyota 1.33 Dual VVT-i consumes 5 l petrol at 90 km/h, ~6 l LPG after conversion [Eidems, #16599232].