Which is thicker 10w30 or 20w50

The automobile industry has a classification system that is used to classify the performance levels of engine oil. In this article, I am going to compare one of the two most popular oil types , the 10w40 and 20w50 so that you get clarity on which type of oil to use. A 10w40 oil has 40 units between the two-scale numbers, and a 20w50 has 50 units between the two-scale numbers. This is very important because engine oil behaves differently in cold temperatures than it does at high temperatures.

The oil will thicken up at low temperatures and therefore it cannot lubricate as well. Automotive engines are designed to run on oils that are in between two extremes, thinner oils, and thicker oils. The 20th viscosity grade i. Just remember to stick to the viscosity grade that is prescribed by the vehicle manufacturer — do not make a wild guess about what viscosity grade you should use.

Keep in mind that most cars today are built to run on 10w40 oil exclusively throughout their entire lives. If you have a newer car, it is recommended that you stick to 10w It should be noted that if you do a proper oil change on any car in summer with 10W40 or 20W50 there should not be problems with sludging as long as you change the oil regularly.

This also applies to winter vehicles — as long as you change the motor oil at regular intervals, it is not necessary to use a thicker and more expensive 10w40 oil. From what has been discussed above, it is clear that the oil you should use depends on the vehicle, what season it is, how fast you drive the vehicle, and other factors.

Modern engines are made almost to perfection, with very low tolerance and with a very high degree of precision. Unlike engine from previous generations, which suffered from relatively uneven grinding surfaces and had leakage issues over time owing to engineering limitations, modern engines are built with almost atomic precision. This development in engine technology has allowed auto makers to recommend engine oils which flow better and allow for better cold starts and provide protection from the very first stroke of the piston.

Also, motor oils which flow better allow for much less resistance as compared to their thicker counterparts, thus enhancing fuel efficiency and refinement significantly. The design and construction of these engines insulates them to a very large extent from the outside temperature.

And since modern engines are also built to much smaller mechanical tolerances they are designed to use the lighter weight, more flowy engine oils. Using thicker engine oil, like a 20W specification would make the oil pump work very hard to get the lube flowing.

This not only loads the fuel pump up, but also makes it difficult for the mechanical parts to move. As another example, Maruti Suzuki, on its official driving tips page suggests that using heavier engine oil than recommended can lead to a decrease of in fuel efficiency to the tune of 2 percent or more.

Mine says 5w30, so that's what I use. So if I'm having a problem with cold starts, but I'm losing compression because my seals are worn out, and I drive long distances at a time - I guess 5w40 would be good for my car? Ameesh Lifer. Apr 3, 23, 0 0. Originally posted by: jumpr The first number is its cold start viscosity. OS Lifer. Oct 11, 15, 1 Originally posted by: OS Originally posted by: jumpr The first number is its cold start viscosity.

Oct 9, 10, 0 0. Apr 29, 48, 14 Originally posted by: Ameesh Originally posted by: jumpr The first number is its cold start viscosity. Vette73 Lifer. Jul 5, 21, 8 0. Originally posted by: mugs Originally posted by: Ameesh Originally posted by: jumpr The first number is its cold start viscosity.

Feb 18, 30, 5 Oils of today are called "multi-viscosity". A 10w oil has the flow characteristics of a 10 weight when cold so lube can be rushed to where it needs to go but a 30 weight when at operating tempeature. It gets thinner. The viscosity diferential is less from hot to cold with a 10w then with a straight 30 weight.

It still gets thinner. KGB1 Platinum Member. Dec 29, 2, 0 0. It is rather odd, GM recommends to use 5w30 on my 01 Astro 4. Jan 28, 2, 0 0. My car has always been run on tractor oil No idea what viscosity because i get it free, could this be harming the engine?

Sep 16, 2 1 Vette73 said:. Don't use 5W20 it is aq gimmick that Honda and ford came up with to save money on fees the goverment charges for gas milage per car. The oil they chose to use was a little thinner and was used to help with fuel consumption. The thicker the oil, the more power it takes to operate the engine. However there are some oils that do a better job of protecting your engine based on there weight.