Liqui Moly 8343 vs 2509 vs Wynn's 18073 vs 76401 vs Goodyear 5-in-1: Clean your fuel

Diesel fuel additives5 products

Quick verdict

Stop guessing and start cleaning

If you want pure injector cleaning, the Liqui Moly 2509 is the gold standard for most drivers. For a deep professional-grade clean, go with the Wynn's 76401, while the budget-conscious should stick to the standard Liqui Moly 8343.

Side by side

FeaturePhoto of Liqui Moly 8343Liqui Moly 8343Photo of Liqui Moly 2509Liqui Moly 2509Photo of Wynn's 18073Wynn's 18073Photo of Wynn's 76401Wynn's 76401Photo of Goodyear 5-in-1Goodyear 5-in-1
Price€15.00€17.50€8.99€23.29€12.95
Targeted CleaningThe Goodyear 5-in-1 covers the widest range of components beyond just the injectors.System wideInjectors & combustion chamberInjectors & fuel systemDeep system treatment5-in-1 (Turbo, DPF, EGR, etc) (winner)
VolumeThe Liqui Moly 2509 and Wynn's 76401 give you the most bang for your buck in volume.250 ml500 ml (winner)325 ml500 ml300 ml
CompatibilityLiqui Moly 2509 explicitly handles the DPF concern, which is vital for modern diesels.UniversalDiesel w/ or w/o DPF (winner)Up to B30UniversalAdvanced systems

Product by product

Liqui Moly 8343

Budget maintenance

A solid, no-nonsense additive for basic fuel system upkeep. It won't perform miracles but keeps things running clean.

What We Liked 👍

  • Very simple to use
  • Trusted heritage brand

What Could Be Better 👎

  • Smaller container size
  • Effects can be subtle

Liqui Moly 2509Our pick

Daily drivers

This is my go-to for keeping injectors firing cleanly. It does exactly what it says on the tin without any gimmicks.

What We Liked 👍

  • Boosts cetane levels
  • Great for older engines

What Could Be Better 👎

  • Larger bottle can be messy

Wynn's 18073Best value

Frequent cleaning

An affordable option that gets the job done for regular maintenance. It is an honest cleaner that doesn't overpromise.

What We Liked 👍

  • Very budget friendly
  • Solid cleaning performance

What Could Be Better 👎

  • Bottle design needs a funnel

Wynn's 76401

Heavy-duty restoration

When your engine feels sluggish, this premium treatment brings out the big guns. It is professional grade for a reason.

What We Liked 👍

  • High-power detergent action
  • Excellent for tired engines

What Could Be Better 👎

  • Higher price point

Goodyear 5-in-1

Total system cleanup

This one targets the whole alphabet of diesel issues, from EGR to DPF. It is the Swiss Army knife of additives.

What We Liked 👍

  • Targets turbo and EGR
  • Modern formula

What Could Be Better 👎

  • Niche for specialized needs

Let's talk brass tacks

If you are looking at these, your engine is likely feeling a bit like a Sunday morning after a Saturday night out. You need to clear the pipes. The Liqui Moly options are the reliable workhorses here. The 2509 is more concentrated and better for engines that have seen a few miles, while the 8343 is your light-duty maintenance additive.

Wynn's offers a similar split. The 18073 is your basic, affordable cleaner, but if you want to fix a specific performance drop, the 76401 is the one I reach for in the shop. Then there is the Goodyear 5-in-1. It is a newer player that tries to solve everything at once. It is great if you have a modern car with a complex exhaust system, but don't expect it to replace a proper mechanical rebuild if your turbo is actually toasted.

The difference between a fix and a band-aid

Here is the deal: these cleaners can strip away carbon and help your spray pattern, but they aren't going to fix a cracked injector or a blown gasket. If your engine is running rough, these are a cheap first step before you start pulling parts off. Always pour them into a near-empty tank before you fill up to ensure they mix properly. If you just dump them in after filling, you are relying on the sloshing of the road to do the mixing for you, and that is just amateur hour.

The final wrench turn

If you want the best all-rounder, go for the Liqui Moly 2509. It is proven, effective, and won't let you down. If your car is showing serious signs of soot buildup across the board, grab the Goodyear 5-in-1 to clean the whole system at once.

For those just wanting to keep things cheap and cheerful, the Wynn's 18073 is hard to beat for the price. Just remember, keep up with your filter changes too, because no additive can clean a clogged fuel filter.

Prices on amazon.es as of October 16, 2026. Prices may change.

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  • Diesel maintenance
  • Fuel additives
  • Engine care
  • Injector cleaner