Lighter wheels can improve handling by reducing unstrung mass, allowing suspension to follow the terrain more closely and thus improve grip, however not all alloy wheels are lighter than their steel equivalents. Reduction in overall vehicle mass can also help to reduce consumption. Cheaper alloys used are usually not corrosion-resistant. Alloys allow the use of attractive bare-metal finishes, but these need to be sealed with paint or wheel covers. Even if so protected the wheels in use will eventually start to corrode after 3 to 5 years but refurbishment is now widely available at a cost. In contrast, steel wheels are usually pressed from sheet metal, and then welded together and must be painted to avoid corrosion and/or hidden with wheel covers/hub caps.