One of the most important features of our spark plugs is the U-groove ground electrode. DENSO’s patented U-groove spark plugs enable complete combustion by allowing the spark to fill the gap created by the ’U’ shape.

The ball of fire created in the U-groove develops a larger and hotter flame front that eliminates excessive fouling and erratic starts resulting from poor fuel mixtures. The U-groove is located on the ground electrode - the place that is least affected by wear. This ensures that the benefits of the U-groove last the entire lifetime of the spark plug.

U-Groove is indicated by the "U" in the typecode e.g. K16R-U11, W20EPR-U

Online Spark Plug Catalogue
Click on the image below and visit our online spark plug catalogue to find the correct spark plug for your engine.