There is a hot topic about cars these days. A Mercedes Benz owner went to the 4S store for daily maintenance and replaced the spark plug after 20000 kilometers,

来说，奔驰在本土地区通常都是8万更换火花塞，根据国内油品改成6万更换，可是在部分地区由于油品质量问题发动机产生爆震高温，4万左右时火花塞负极就会被烧化，烧灼产生的碎渣极有可能掉进活塞缸壁之间，从而造成拉缸损坏发动机。

First of all, Mercedes Benz usually replaces the spark plug at 80000 km in the local area, which is changed to 60000 km according to the domestic oil products. However, in some areas, due to the oil quality problem, the engine produces knock and high temperature, and the negative electrode of the spark plug will be burned at about 40000 km, and the slag produced by burning is likely to fall between the piston cylinder wall, resulting in cylinder pulling and engine damage.

有一种说法是，发动机通常享受三年或10万质保，如果在4万时发动机损坏势必会对厂家造成很大利益损失，口碑、投诉也会受到不利影响，所以保养手册与海外版不同，采取2万更换火花塞的办法。

There is a saying that the engine usually enjoys a three-year or 100000 km warranty. If the engine is damaged at 40000 km, it is bound to cause great loss of interests to the manufacturer, and the reputation and complaints will also be adversely affected. Therefore, unlike the overseas version, the maintenance manual adopts the method of replacing the spark plug at 20000 km.

单凭油品说事显然有甩锅嫌疑，众所周知，火花塞根据极点材料不同、等级不同，其使用寿命也会不同。按从低到高划分分别是：镍合金、铂金、铱金、依铂金、双铱金（针对针）、钌合金火花塞。奔驰原厂采用铂金和铱金材料的火花塞，通常使用寿命在5~8万之间，由于油品不好造成火花塞出现沉积、电极消耗、MMT污损、熏黑、烧灼等现象，出现问题的火花塞部分仍可以继续点火工作，但是点火原本的电击点会发生位移！影响火焰燃烧。

Oil alone is obviously suspected of throwing the pot. As we all know, the service life of spark plugs will be different according to different pole materials and grades. From low to high, they are: nickel alloy, platinum, iridium, platinum, double iridium (for needle), ruthenium alloy spark plug. The spark plugs made of platinum and iridium in Mercedes Benz's original factory usually have a service life of 50000 ~ 80000 kilometers. Due to poor oil products, the spark plugs appear deposition, electrode consumption, MMT fouling, blackening, burning and other phenomena. The spark plugs with problems can still continue to ignite, but the original electric shock point of ignition will be displaced! Affect flame combustion.

除了油品外为何奔驰发动机需要2万更换火花塞呢？这就要提到奔驰发动机的第三代汽油缸内直喷技术了。奔驰第三代汽油缸内直喷技术名为BlueDIRECT缸内直喷技术，通常缸内直喷是靠高压油泵+多次喷油构成，但是奔驰这套可没有这么简单，在一个冲程内更多可实现5次燃油喷射（马自达SKYACTIV-G为三次喷射，一般为两次喷射），ECU给出指令控制火花塞在1毫秒时间内需点火4次，也就是4次火花释放（稀薄燃烧技术）。配合缸内涡流设计让混合气达到燃效效果，同时也能满足苛刻的排放法规。

In addition to oil, why does Mercedes Benz engine need to replace spark plugs for 20000 kilometers? This is about to mention the third generation gasoline direct injection technology of Mercedes Benz engine. Mercedes Benz's third-generation gasoline in cylinder direct injection technology is called bluedirect in cylinder direct injection technology. Generally, the in cylinder direct injection is composed of high-pressure oil pump and multiple fuel injections, but Mercedes Benz is not so simple. It can achieve up to five fuel injections in one stroke (Mazda skyactiv-g has three injections, usually two injections), ECU gives a command to control the spark plug to ignite 4 times within 1 millisecond, that is, 4 spark releases (lean combustion technology). With the swirl design in the cylinder, the mixture can achieve the best combustion effect and meet the stringent emission regulations.

由于点火次数的增加带有缸内直喷技术的发动机会缩短火花塞使用寿命，奔驰BlueDIRECT在做功冲程需点火四次也就是进一步缩短了火花塞寿命，再加燃油油品问题，所以奔驰发动机每2万更换火花塞也就不足为奇了。

Due to the increase of ignition times, engines with in cylinder direct injection technology will shorten the service life of spark plugs. Mercedes Benz bluedirect needs to ignite four times in the power stroke, which further shortens the service life of spark plugs. In addition, it is not surprising that Mercedes Benz engines replace spark plugs every 20000 kilometers.