- In conclusion, the price of car spark plugs can vary widely depending on the type of plug, the quality of the material used, and the brand. While conventional spark plugs are relatively inexpensive, performance spark plugs and those made from platinum or iridium can be much more expensive. When choosing a spark plug, it's important to consider your vehicle's needs and budget, as well as the quality and reputation of the brand.
ISO 6194-1 1)
6 GUIDELINES TO FOLLOW WHEN CHOOSING AN OIL SEAL

Storage and Handling
Finding oil spots under a parked vehicle can be both worrying and stressful for any vehicle owner. If the seal’s leak is small, oil may start to accumulate on the underside of the engine. But as the leak gets bigger, the oil leak will become visible in the front side of the engine.
Seals, including oil seals, have undergone a great development in recent years and are totally unlike the original product. PTFE has taken over the oil seals market for modern engines mainly because traditional oil seals started causing more and more problems. Such as evaporation of chemical plasticisers from the elastomeric material, which eventually caused engine oil leakage. Now, the focus is more on durability and frequency of servicing.

sheet gaskets.
Replacing a distributor oil seal or gasket
Oil seals are installed beside the bearing while the flexible lip is pressed against the rotating shaft. The casing pressing into the housing holds the seal in place. The sealing lip is essentially lubricated to minimize the risk of overheating due to the generated friction.