Do you drive in the city

Do you drive in the city

Do you drive in the city?

More and more cars drive in congested cities. Many cars never leave the city and only move short distances at slow speeds. This is in fact more challenging for cars than driving every day on a highway.

Engine oil intervals are becoming much shorter in terms of the driven mileage than the usual interval as the engine runs at high heat many hours for only a few kilometers. Regular oil change intervals are estimated based on a mix of high speed and low speed driving.

Hybrid cars start their ignition only at higher speeds and have a very long fuel refill interval. This causes a bad fuel quality in the tank with a lot of water, corrosion and bacteria.

Modern high performance engines with direct injection are often subject to premature ignition problems at low speeds, which is called LSPI - low speed preignition.  LSPI results in engine knocking and can damage the engine.

What happens when you only drive short distances at low speed in traffic?

  1. Your engine oil gets very hot and ages fast. The engine runs the entire time except for cars with Start/Stop technology or Hybrid engines. During low speeds the radiator and surrounding air have a weaker cooling effect. The engine oil gets hot and tends to burn, resulting in ash and sludge in the oil system. To prevent this use engine oils with a lot of friction modifier or add a friction modifier engine oil additive to the engine oil. Watch your oil change interval and change the oil more frequently. When you change the oil, make sure you clean the engine with an engine cleaning additive in the process to remove old ashes and sludge.
  2. Your engine might suffer from LSPI - low speed preignition problems when you accelerate at a low RPM.

    LSPI in engines with direct injection causes knocking and damage to the engine. You can use special engine oil that reduces the negative effects of LSPI and Direct Injection Cleaning fuel additives. Opel requires you to use such additives for some of their engines already to avoid breakdown and many other modern cars with downsized engines suffer from the same problem.

  3. Your exhaust system gets polluted. Exhaust systems are designed to first catch particles and then burn them at high temperatures in the catalytic system or DPF Diesel Particulate Filter. This process is the regeneration of the exhaust and works automatically when you drive at high speed over a longer period of time. Not all particles can be burnt in every exhaust system. For example ash from engine oil that is not designed for cars with DPF will clog and stay in the DPF Filter. This deposit becomes hard like concrete and no cleaning process can remove them. In this case you will have to order a new DPF Filter. Therefore the first step to maintain a clean exhaust system is to use the right engine oil with the OEM approval for your car. The second step is to regenerate the exhaust by driving often 30-60 minutes at high speed or by using fuel additives. You will get the best regeneration result when you use an additive while driving at high speed. Use Diesel Particulate Filter cleaning additives for cars with a DPF Filter and Catalytic System cleaning additives for petrol cars.
  4. Your fuel tank builds up water and corrosion as well as bacteria. You might only refuel every two or three months, when you drive only short distances in your city. Especially in a humid climate the water in the air will enter your fuel system and stay in the fuel tank. The water will cause corrosion and allows bacteria to grow. It can also enter the combustion chamber and cause major damages. To remove the water safely use fuel additives that have such an effect like some injection cleaner additives and fuel system cleaning additives.
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