Nu / G4NA Engine

2.0 MPI Nu (G4NA) – Experiences, problems, fuel consumption and buying tips

If you’re looking at a third-generation Hyundai Tucson and want to avoid diesel engines and their complex exhaust after-treatment systems, you’ve probably come across the 2.0 MPI petrol engine. On paper, it looks very “old school” – no turbo, no high-pressure direct injection, simple construction. However, is this simplicity a guarantee of reliability, or does it hide serious flaws? As someone who has spent years analyzing the Korean car industry, I can tell you this engine has two faces.

Key points in short (TL;DR)

• Biggest drawback: The notorious issue with cylinder wall damage (scuffing) and piston “knock”, especially on models produced before 2017/2018.
• Timing drive: Uses a chain, which is generally durable, but should be inspected at higher mileage.
• LPG (Autogas): This is an MPI engine, which makes it an ideal candidate for LPG conversion. It handles it very well.
• Performance: It’s not a racer. For the Tucson’s weight, 192 Nm of torque is modest. It needs high revs for overtaking.
• Maintenance: Regular maintenance is cheaper than on a diesel (no DPF, no dual-mass flywheel on automatics, no turbo), but fuel consumption is high.
• Recommendation: Look for examples produced after 2017, which (mostly) have oil squirters installed for piston cooling.

Contents

• Technical specifications
• Reliability and maintenance
• Specific parts and costs
• Fuel consumption and performance
• Additional options and modifications
• Gearbox
• Used car buying tips and conclusion

Technical specifications

Parameter	Data
Engine code	G4NA (Nu family)
Displacement	1999 cc (2.0 L)
Power	113 kW (153 hp) @ 6200 rpm
Torque	192 Nm @ 4000 rpm
Injection type	MPI (Multi-Point Injection) – Indirect
Air charging	Naturally aspirated (No turbo)
Engine block	Aluminum with thin steel liners

Reliability and maintenance

Does this engine have a timing belt or a chain?

The G4NA engine uses a timing chain. In theory, this chain is designed to last the entire service life of the engine, but in practice a detailed inspection (or preventive replacement of the chain kit) is recommended at around 150,000 – 200,000 km. Chain stretch is not as common as on some German competitors, but the hydraulic chain tensioner can weaken, which leads to rattling on cold start.

What are the most common failures on this engine?

We need to be completely honest here – the G4NA has one major factory flaw, especially on models up to 2017:

• Cylinder wall damage (scuffing): Due to poor piston cooling and tight tolerances, the piston overheats, expands and starts to “scrape” the cylinder wall. Symptoms: A characteristic metallic knocking sound (like a diesel) while the engine is cold, which later turns into constant knocking and increased oil consumption. Hyundai later (late 2017/2018) added oil squirters that cool the pistons from below, which significantly reduced this problem, but did not completely eliminate it.
• Catalytic converter: The ceramic honeycomb of the catalytic converter can disintegrate. The danger lies in the fact that the engine can (due to backpressure and variable valve timing) “suck” ceramic dust back into the cylinders, which instantly destroys the engine (it sands down the cylinder walls).
• Oil leaks: Often occur at the valve cover and crankshaft oil seal.

At what mileage is the major service done?

Since the engine has a chain, a classic “major service” (timing belt replacement) does not exist. Instead, the auxiliary belt set (alternator/AC belt, tensioners, idlers, water pump) is usually replaced at 90,000 – 120,000 km or every 5–6 years.

Oil: quantity, grade and consumption

The sump holds roughly 4.0 liters of oil (buy a 4L or 5L canister). The recommended grade is 5W-30 (ACEA A5/B5 standard). Due to lubrication issues around the pistons, I recommend changing the oil at a maximum of 10,000 km or once a year.

Does it burn oil? A healthy engine should not consume more than 0.5L per 10,000 km. However, if the engine starts consuming more than 0.5L per 1,000 km, this is a clear sign that the cylinder walls are damaged (scored) and that the engine is due for a full rebuild (re-sleeving).

Specific parts (costs)

Does the engine have a dual-mass flywheel?

It depends on the gearbox. Versions with an automatic transmission (which are more common in the Tucson) do not have a dual-mass flywheel; they use a torque converter. Versions with a manual gearbox generally have a conventional solid flywheel on MPI versions, which makes clutch kit replacement significantly cheaper. Still, check by VIN, as some models for Western markets had variations.

What kind of injection system does it have and are the injectors problematic?

This is a major advantage of this engine. It uses an MPI (Multi-Point Injection) system. The injectors are simple, inexpensive, operate at low pressure and are extremely resistant to poorer fuel quality. Injector failures are rare.

Turbo, DPF, EGR?

This is paradise for those who hate modern emissions systems:

• Turbo: NONE. No turbocharger to fail, no intercooler.
• DPF filter: NONE.
• EGR valve: There is an exhaust gas recirculation system, but it is not prone to clogging like on diesels because petrol engines produce less soot.

Fuel consumption and performance

What is the real fuel consumption in city driving?

Do not trust the official figures. The Tucson is a heavy car (over 1.4 tons) with a naturally aspirated petrol engine.
City driving: Expect between 10 and 12 liters per 100 km. In winter and heavy traffic it can go up to 13–14 liters.
Highway / open road: It can drop to 7–8 liters if you drive gently.

Is this engine “lazy”?

Yes, by today’s standards it is somewhat sluggish. With 192 Nm of torque available only at a relatively high 4000 rpm, you don’t get that “kick in the back” like with turbo diesels (CRDi) or turbo petrol engines (T-GDI). It is perfectly adequate for relaxed driving, but overtaking on country roads requires dropping two gears and revving the engine close to the redline.

What is it like on the motorway?

At 130 km/h in sixth gear, the engine spins at around 3,000 – 3,200 rpm (depending on the gearbox). Up to that speed, noise is acceptable, but fuel consumption rises exponentially. Sound insulation in the Tucson is good, so the engine doesn’t tire you too much, but the lack of power is noticeable on long climbs.

Additional options and modifications

Is this engine suitable for LPG (autogas) conversion?

Absolutely YES. This is one of the best modern engines for LPG conversion. Thanks to indirect (MPI) injection, installation is simple, cheaper (a standard sequential system, no need for a direct-injection LPG system) and the system pays for itself quickly given the high petrol consumption. Recommendation: Be sure to install a system with valve lubrication (“valve saver”) or set up the software to inject a small amount of petrol at high revs to cool the valves.

Remapping / chip tuning (Stage 1)?

Don’t waste your money. On a naturally aspirated engine without a turbo, a remap will give you maybe 5 to 8 hp, which you won’t really feel in everyday driving. The only noticeable change might be a slightly sharper throttle response.

Gearbox

Which gearboxes are fitted?

• Manual: 6-speed. Precise and easy to use.
• Automatic: 6-speed, conventional hydraulic (torque converter). Manufactured by the Hyundai/Kia group.

Gearbox failures and maintenance

The automatic is extremely reliable and comfortable. It doesn’t have the jerky behavior of DCT (dual-clutch) gearboxes. Its only downside is that it “eats” a bit of power and increases fuel consumption.
Automatic service: Although the manufacturer often claims “fill for life”, you should definitely change the transmission fluid every 60,000 – 80,000 km. The cost of replacement is moderate (“mid-range expensive”).

On the manual gearbox, the clutch kit is a wear item. Replacement is not expensive because there is usually no dual-mass flywheel. The clutch is light and pleasant for city driving.

Buying used and conclusion

Buying a used Tucson with the 2.0 MPI engine requires caution, solely because of the piston-related issues.

What to check before buying?

1. Cold start: Insist that the engine is completely cold when you start it. Listen for a characteristic knocking (knock-knock-knock) that follows engine rpm. If it goes away once the engine warms up, this is the initial phase of cylinder damage. If it keeps knocking when hot – walk away from that car.
2. Endoscopy: If you are a serious buyer, take the car to a workshop and ask them to inspect the cylinder walls with a camera (endoscope) through the spark plug holes. If there are vertical scratches, the engine needs a rebuild.
3. Catalytic converter: Check the condition of the catalytic converter honeycomb.

Final verdict

The Hyundai Tucson 2.0 MPI is a good choice for calm drivers who cover lower annual mileage or plan to install LPG. It is ideal for those who are afraid of turbo failures, DPF issues and expensive injectors. However, the risk of catastrophic engine failure (cylinder scuffing) is real. My advice: look for facelifted models (late 2017 and newer) or examples that have documented engine work / installation of oil squirters.