DENSO Iridium TT: most progressive spark plugs

Hi there! I’m Liam Brooks, automotive expert and author of I’ve tested a dozen of spark plugs on difference vehicles: GMC Sierra, Hyundai Elantra, Ford Focus and many more.

The new Iridium TT spark plugs from the Japanese company DENSO boast the highest concentration of iridium in comparison with any other plug on the market. This results in excellent flammability, optimum engine performance and significant fuel economy. Another distinguishing feature of the Iridium TT spark plugs is the Super Ignition Plug technology, which is based on a combination of an ultra-thin counter-iridium center electrode and a platinum side electrode.

The central iridium electrode of the DENSO Iridium TT spark plug has the smallest diameter in the world – only 0.4 millimeters, and the counter electrode 0.7 millimeters in diameter increases spark energy and reduces heat loss. Spark plugs with SIP technology from other manufacturers are now used in supercars and luxury cars. The ultra-thin iridium electrode makes the ignition system even more efficient by significantly increasing the ignition efficiency and reducing heat losses during start-up.

The design using iridium and platinum in the Iridium TT spark plugs provides them with a resource of 120 000 km, which is about five times more than that of standard nickel. DENSO Iridium Spark Plugs can be selected for almost any vehicle whose engine complies with Euro 5 / Euro 6 emission standards. As for the higher price, it is successfully offset by savings in the car service. You can change these candles every five years.

It’s hard to believe, but the fact is that such a simple operation as replacing conventional spark plugs with iridium ones can make driving a car more pleasant and fuel consumption minimal. So why not take this opportunity?

Here is a review from the happy customer:
“It was nearing the time to replace plugs on my 2004 Ford Focus, and after hearing some radio advertisments for this plug from one of the local DJ’s, I decided to look into getting it instead of the Honda recommended replacements. After all, the Honda is now old, and manufacturers often (or rather, never) update their recommendations after a vehicle model is out of production. I’ve been burned on ‘snake oil’ plugs before (yes, I bought Splitfires way back when, and see my other reviews about the Bosch +4 plugs), so I guess I’m a glutton for punishment.”

I’ve picked the best spark plugs for Ford Focus, check it out on

Best regards, Liam Brooks