It depends on the engine you’re putting them in. Platinum spark plugs will make a difference to your wallet, being a touch pricier than their copper counterparts, but will also last significantly longer, giving value to your extra spend.

Because they last longer, you’ll also save yourself the added effort of replacing them so frequently. Copper spark plugs should last between 20k and 30k miles, whereas your platinum plugs will easily double that. So if you’re hoping to navigate plug changes, iridium spark plugs will achieve the 100k miles expected from modern cars these days. They can actually take you far further, but they’re not designed to, so you won’t be doing yourself—or more accurately—your engine any favours if you let them run much further than their recommended guidelines.

Mid-range budget for a good quality plug

Platinum plugs sit neatly between traditional copper spark plugs and iridium options in the price battle and performance. But what kind of difference will they make to how your car runs? Most of the time, you won’t notice the difference, only that they last longer between changes, but that doesn’t necessarily mean they don’t have an impact on your engine performance.

As with most things in the modern consumer market, you get what you pay for. So why are they better, and why do they cost that little extra?

As we’ve mentioned, a platinum spark plug will retain its spark performance for over 60k miles. If your car is designed to run on double platinum plugs (where the spark is delivered in two parts of the engine cycle), you’ll achieve nearer the 100k-mile mark.

Platinum – a rare and valuable metal that’s excellent for modern engine spark plugs

Platinum is one of Earth’s rarest metals. That also makes it pretty valuable. However, as well as being a highly sought after material for high-end jewellery, it also makes pretty good spark plugs.

Why? Well, it offers incredible resistance to corrosion and erosion under the harshest conditions. There aren’t many places as harsh as the insides of the cylinders in a modern engine amidst continuously igniting the fuel and those high pressures. Platinum’s quality in spark plugs is partially down to its high melting point of 3600F and its much harder composition than copper.

With its resistance to erosion and damage, the lifespan of each plug is extended and gap growth reduced, putting less strain on the voltage required to form each spark as the miles tick by.

Don’t be fooled into thinking copper plugs are low quality because they’re cheaper

Copper spark plugs have done motorists proud for years. However, just because they’re the cheapest plugs available doesn’t mean they’re low quality; it just means that they cost less to make and that they don’t last as long as the more costly options.

The problem with copper plugs is that they need replacing far more frequently, requiring more maintenance and effort from the driver. We live in a world where we strive for convenience, so a plug that lasts longer scores higher on our motoring needs.

As far as performance goes, many custom-tuned and older model cars still use copper plugs as standard, as they require less voltage to deliver a strong spark. In some cases, drivers may achieve a slight increase in power and mileage, but possibly not so much as they’d notice.

Advantages of platinum spark plugs over traditional copper options

Platinum is significantly harder than copper and has a far higher melting point. As we said earlier, this means that platinum spark plugs will last longer, making service stops fewer and further between.

However, being able to handle much more heat in a far better manner, your platinum spark plugs will burn off the deposits left by the burnt fuel far easier. So, with less build-up on the electrodes, the integrity of each plug remains higher for longer, hence their extended lifespan.

The disadvantages of platinum spark plugs against iridium equivalents

As engine technology developed, so did the components they housed. The new tech offered far better control and precision timing when it came to ignition coils. Smaller coils fitted onto the spark plugs delivered greater control over each cylinder event, managing new performance levels, economy, and emissions.

Smaller ignition coils with lower outputs led to ‘fine wire’ centre electrodes with centre wires as narrow as 0.6mm. Iridium was just the right type of metal to offer a higher efficiency level with a tiny centre wire yet robust and durable enough to deliver extended use, far better than platinum and copper.

Upgrades are okay; downgrades aren’t

If an engine is built to run on the latest technology where iridium plugs are fitted as standard, do yourself a favour, and replace them like-for-like. Downgrading to a set of platinum spark plugs might save you a few pounds at first, but if they can’t deliver the same standard of performance and spark required of them, it could soon lead to issues with your ignition system you’d rather avoid.

If you’d like to invest in a longer-lasting spark plug, upgrading from copper to platinum would be a fine switch for most vehicles. If you have any doubts, always consult your mechanic—especially when it comes to older or vintage models. Copper is often still the best option for those types of cars.

Our experts will happily guide you through the best options for your vehicle, keeping you safe and sound on the roads and your car in tip-top condition.