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Bosch vs NGK vs Denso Spark Plugs: Comparison Guide

Looking to buy new spark plugs? Want to replace your worn-out sparks with OE quality?

NGK, Bosch, Denso spark plugs are three top-quality plugs that are ruling the market and to be true, there’s haven’t been much discussion about sparks plugs before these phenomena.

It’s not just the performance that makes these plugs so desired, it’s the whole package considering applicability, built quality, and lifespan.

Now, it’s okay to be a fan of a particular brand but personally, I try and stick to the same brand as it helps the vehicle’s perusal.

From my experience, Japanese cars provide NGK or Denso as stock sparks and Bosch is more preferred by the German carmakers.

If you are new to auto parts, you can hardly realize the vast difference between the plugs. So, to clear out the confusion, we’ve constructed a full article comparing NGK vs. Bosch vs. Denso. And at the end of the article, you’ll have a clear perspective of your purchase decision.




NGK Spark Plug
Bosch Plug for car
Denso plug

Utterly reliable and industry best longevity

Great value for the price

Lasts four times longer than platinum or copper spark plugs

Iridium tip with metal plating that eradicates corrosion or seizing

Double platinum on the tip

Amplify performance and gas millage

Superb acceleration with high fuel economy and durability at the same time

Good combustion, outstanding fuel efficiency

Anti-seize, wear, and corrosion resistant

NGK Plug

NGK Plug

Has there ever been a discussion where this very plug didn’t make a list? Not something I ever witness. If you surf around blogs and forums, you’ll see these NGK plugs as a top pick.

Built with iridium tip with metal plating and rounding up, its phenomenal performance has brought the company supremacy it deserved.

What so good about the introduction of iridium? They come with a very high heat range, which is best suited for hot engines in modern cars.

The electrode wire inside is super thin, destined to provide you with fuel efficiency, engine feedback. These plugs can easily last till 80,000 miles, almost twice compared to the sparks with a copper core.

Once you install double iridium-powered plugs, you’ll notice an enhanced vehicle boost compared to copper spark plugs. Thanks to the combustion chamber that lets the air and fuel mix in the right amount.

Final rating

With the latest materials and technology, the NGK plug is ideal for how the industry evolved.

In my opinion, it is easily one of the best spark plugs regardless of time.

NGK has always been a top choice for people to thrive for performance. I haven’t seen spark plugs pull off this sort of performance, maintaining an eye-catching lifespan.

Denso Plug

Denso Plug

Denso is a globally renowned company that has earned its place producing auto parts and home appliances. The Japanese company has a pretty diverse product line, and of all that, the spark plugs stand on top.

The platinum sparks are budget-friendly and go easy on your wallet. But you’ll notice no compromise in terms of fuel efficiency or durability you desire.

Technically I found this product to be very sound indeed. Twin-tip is a feature that is only present in these plugs. The whole attire of the product welded in 360-degree using laser.

Double platinum on the tip, platinum powered disc, and whole construction coated with platinum makes the sparks an eccentric OE choice spark. Local dealers around you will mostly recommend this brand considering its wide availability.

A unique feature of the Denso plugs is that they use purified alumina powder instead of nickel alloy in the insulator. The powder helps Increase plug lifespan by maximizing thermal opacity.

Final rating

Denso is the go-to spark for car manufacturers, and we see them in cars a lot. Just ask around you, the majority of cars are equipped with Denso plugs. The fact that they are economical compared to other OE quality plugs makes Denso even more lucrative than that it already is.

I’ve looked up reviews for this product and even used the Denso spark plugs once in my Mazda 121 metro and was very satisfied with the performance. Being one of the best spark plugs in the market, it is obvious.

Bosch Plug

Bosch Plug

Bosch has been in the market since 1902, and they proved to be the sophisticated manufacturer. Anyone ever using a Bosch product indeed became a fan of it; at least that was the case for me.

Bosch has intensive research facilitates that accommodates new technology and infuse that into the product. With this double iridium spark plug, you get the best of OE technology.

Let me summarize their supremacy in short—

first, the double iridium, then continuous laser welding to ensuring reliability, longevity, and heat control.

Secondly, the super-thin wire design (0.06mm) is the main reason why you get exceptional ignition, voltage control, and relentless cold start even in the extreme of conditions.

And lastly, the insulator is uniquely ribbed, so there’s no chance for a misfire of any sort. Also, for this very reason, you don’t need to gap the plugs. The shells of the Bosch plugs are nickel-plated to withstand seize and corrosion too.

Final rating

Concrete facts along with customer reviews support the statement that the Bosch plug is the answer for the world’s most advanced engines. Starting from their manufacturing to quality control, you’ll see the definition of professionalism and compassion towards the customers.

Putting aside all the talks about NGK vs. Bosch, Bosch has an extensive customer base. And rightly so, with the premium performance you get with this spark plug, it’s hard to ignore the satisfaction that comes with it.

Bosch vs NGK vs Denso Spark Comparison table

Product name



Gapping requirement


Wire details

OE matched spark position





NGK iridium IX

Iridium built, good combustion chamber

Pre- gapped, may need additional adjustment

Ultra-fine wiring of 0.6mm


50,000 miles

60 days for any defects found


Denso Platinum TT

Dual platinum, along with platinum disk

Very minimum gapping needed

Platinum electrode tip


60,000 miles

12 months warranty


Bosch automotive Double iridium

Double Iridium, ribbed insulator, nickel-plated shell

No need

Ultra-thin 0.6mm wire


10,000 miles

7 years satisfaction guaranteed


Also read: Key Differences Between Champion vs Ngk Spark Plugs

Which is better, NGK or Denso?

Let me get some facts straight before you go on with NGK vs. Denso.

Both NGK and Denso are iridium spark plugs. The metal in use is hardly conductive compared to the copper ones. The sparks can function in freezing weather and still be able to deliver an extensive lifespan.

The lifespan of these iridium plugs can be twice as much as regular plugs. Iridium spark plugs function for 40-60,000 miles on average.

Another positive note is that the plugs are utterly stable and don’t show any sign of a gap regarding times. With the platinum ones, you will not have this luxury at your disposal.

Having said their similarities, they too have their fair share of differences, but you can’t go on and declare a winner. I’ll tell you why.

Denso and NGK spark plugs are very common in Japanese vehicles, but the iridium in Denso is more rigid than the NGK.

But the diameter of the electrode in Denso Sparks declines faster than an NGK plug which another reason why the NGK can last astonishingly more than the competitors, but Denso wins the power-producing segment.


Is NGK a good brand?

Yes, NGK is one of the most delicate spark plugs in its range available in today’s market. This Japanese brand manufactures its plugs using double iridium rather than double platinum, ensuring that the sparks run smoothly and provide excellent durability. The targeted customer base for NGK has always been the performance enthusiasts who constantly demand enhanced throttle response accompanied by the better gas millage. Even the smallest detail, like silver transition metal, has impressed me a great deal.

Are Bosch Spark Plugs good for Mercedes Benz?

Bosch plugs are a very eccentric choice for your Mercedes Benz. Bosch sparks are OE choice sparks with the balance of fuel efficiency and superior performance. We are talking about German cars with top-class engines, so it is safer to opt for a Bosch plug than OEM quality. It’s widespread to talk about Bosch vs. NGK. And there’s no point denying that they are both superior plugs, but in terms of Benz, Bosch goes the extra mile.

Another great plus, Bosch plugs are colder plugs compared to other brands. Using hotter plugs in Mercedes may result in pre-ignition issues. For more information, you can read the 5 Best Spark Plugs For Mercedes Benz.

Also read: Best Spark Plugs for Honda: Find the Perfect One


After considering all the facts, we’ve concluded that the NGK is the comprehensive solution to your spark plug needs. Iridium, platinum, and copper this is in order in terms of quality and technology.

Denso plugs are more of a budget solution to your need. These two brands are known for their quality.

New Cars have the best spark plugs, of course. So, vehicle owners should always try and replace the plugs with OE quality auto parts.

You may also check our other Auto Parts articles:

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