📋

Key Facts

  • Using a cheaper oil different from the manufacturer's specification can cause sludge and clog oil passages.
  • The belief that older engines require thicker oil is a myth; the same oil type should be used throughout the engine's life.
  • Modern engines with oil-bathed timing chains can suffer catastrophic failure if the wrong oil corrodes the chain.
  • Using unapproved oil can void the vehicle's warranty and lead to expensive engine repairs.

Quick Summary

Experts warn that switching to a cheaper engine oil to save money is a dangerous mistake that can lead to severe engine damage and financial loss. When manufacturers develop an engine, they determine the specific oil type required to handle temperature, gaps, and rotation. Using a different lubricant can cause sludge, clog oil passages, and lead to excessive wear on moving parts.

A common myth suggests that older engines require thicker oil, but specialists maintain that the same oil type should be used for the engine's entire life if maintenance is performed correctly. Furthermore, modern vehicles often use oil-bathed timing chains that are highly sensitive to chemical composition; the wrong oil can corrode these components. Ultimately, using the wrong oil can result in a blown engine, loss of warranty coverage, and expensive repairs.

The Dangers of Using the Wrong Lubricant

Many drivers look for ways to cut costs, but automotive specialists warn that engine oil is not the place to save money. Using a lubricant that is cheaper than the manufacturer's recommendation can cause significant damage. According to automotive repair experts, manufacturers determine the specific oil type required to meet the engine's demands for temperature, gaps, and rotation.

Using a lubricant different from what is specified can cause sludge. This sludge clogs oil passages, leading to excessive wear on moving parts. The result is often a massive financial loss, both in repair costs and the time the vehicle remains out of service for an engine overhaul. Experts emphasize that regardless of the vehicle's mileage, the oil must meet the technical specifications indicated by the manufacturer.

"Trocar o óleo correto do seu carro, por um mais barato? Nem pensar"

Specialists explain that the formulation of a lubricant is meticulously balanced to achieve high performance. Aditivos present in the oil, such as anticorrosive and antioxidant agents, can conflict if mixed, potentially leading to the formation of sludge. Therefore, using the wrong oil is not just inefficient; it is actively destructive to the engine's internal environment.

"Trocar o óleo correto do seu carro, por um mais barato? Nem pensar"

— Tenório Jr, Owner of JR Automotiva

Debunking the 'Thicker Oil for Old Engines' Myth

A prevalent belief in the automotive market is that as an engine ages and parts develop gaps, it requires a thicker, more viscous oil. Experts identify this as a complete myth. If maintenance is performed correctly and on time, the gaps in engine components remain irrelevant and do not necessitate a change in oil type.

Historically, older cars used mineral or semi-synthetic oils to compensate for internal wear, such as gaps in rings, pistons, and bearings. However, this is considered an outdated and incorrect practice. Manufacturers test engines for thousands of kilometers and do not recommend changing the oil specification over the years. In modern engines, the use of semi-synthetic oil is often replaced entirely by synthetic oil.

"É realmente um mito, porque tem que utilizar o mesmo tipo de óleo até o fim da vida do motor"

Using a thicker oil than specified can force the engine to work harder, while an oil that is too thin may fail to provide necessary protection. The goal is to maintain the specific viscosity defined by the vehicle manufacturer to maximize efficiency and fuel economy.

Maintenance Intervals and Oil Types 🛢️

Adhering to the correct maintenance schedule is as crucial as choosing the right oil. The best time for an oil change is indicated in the owner's manual, which is often available online if the physical copy is lost. For example, the Volkswagen Gol Last Edition requires an oil change every 10,000 kilometers or 12 months, whichever comes first.

However, manufacturers list specific "adverse conditions" that require more frequent, preventive changes. These include:

  • Frequent stop-and-go traffic or prolonged idling.
  • Short trips of less than 8 km daily.
  • Long periods of vehicle inactivity.
  • Driving on unpaved, dusty roads or in areas with high industrial pollution.
  • Towing or driving with heavy loads.

For motorcycles, intervals are generally shorter. The Honda CG 160, for instance, requires a change every 6,000 km or 12 months, while the Honda Elite 125 requires it every 4,000 km. There are three main types of oil available on the market:

  • Mineral: Cheaper, less refined, and suitable for older cars (e.g., 20W-50 for a Volkswagen Fusca).
  • Semi-synthetic: A blend between mineral and synthetic, offering better performance at a lower cost (e.g., 15W-40 for a Ford Escort 1.8).
  • Synthetic: The most advanced, offering maximum performance, fuel efficiency, and protection. It is required by all modern factory vehicles.

Critical Risks: Oil-Bathed Chains and Warranty ⚠️

One of the most critical issues with using the wrong oil involves modern engines equipped with oil-bathed timing chains. These chains are located inside the engine and rely on the oil for lubrication and cooling. Using the wrong oil can corrode the rubber materials in the chain, causing it to stretch or break.

If a timing chain snaps due to corrosion, the engine's valves and pistons can collide, resulting in catastrophic internal damage and a very expensive repair bill. Specialists state that the oil must have specific molecules compatible with the elastomers used in these chains.

Beyond mechanical failure, using an unapproved oil can void the vehicle's warranty. Manufacturers explicitly state that only approved oil specifications should be used. Using a non-approved lubricant can lead to:

  • Formation of deposits and sludge.
  • Excessive component wear.
  • Engine overheating and fusion.
  • Increased emissions and environmental impact.
"Se colocar um lubrificante diferente do especificado, pode causar borra, que é um problema que entope os dutos de passagem de óleo e, consequentemente, gerar desgaste excessivo das peças móveis"

While it is possible to temporarily mix oils or top up with whatever is available in a dire emergency to reach a repair shop, this should be done only as a last resort. A full oil change with the correct specification should be performed immediately afterward to prevent damage.

"Se colocar um lubrificante diferente do especificado, pode causar borra, que é um problema que entope os dutos de passagem de óleo e, consequentemente, gerar desgaste excessivo das peças móveis"

— Tenório Jr, Owner of JR Automotiva

"É realmente um mito, porque tem que utilizar o mesmo tipo de óleo até o fim da vida do motor"

— Alexandre Dias, Auto Center Guia Norte