10W-30 and 10W-40 are all four-season oils, but they adapt to different temperatures. 10W-40 can adapt to a wider temperature range, and the use effect of 10W-30 in summer may be slightly worse than that of 10W-40, and it can be used in spring and autumn or when it is not too cold in winter.
In other words, the temperature that 10W-30 can adapt to is 10W-40, but in hot summer, the former is not as good as the latter. From this, you can only see the label of the oil, but you can't see the quality of the oil. Generally speaking, motorcycle oil can be replaced on schedule as long as it is not fake and shoddy.
Method of selecting engine oil:
It is best to use multi-viscosity lubricating oil when choosing engine oil. Lubricating oil (also called multi-grade lubricating oil) has the properties of low temperature light oil and high temperature heavy oil. When multi-grade oil is recommended, one multi-grade oil can replace multiple single-grade oils.
Although multi-grade oil can meet the needs of extremely cold and warm seasons and heavy-duty engines, especially those diesel engines that have no difficulty in starting in cold weather, it is usually recommended to use lubricating oil with single viscosity, which is beneficial to engine lubrication and prolongs engine service life. ?