11/7/2023 0 Comments Car transmission gear ratioWhat this does not mean is your car having 6 gears will automatically make it relaxed at highway, a manufacturer can choose to make 5 gear car more relaxed than your 6 gears one by simply making the last gear extremely tall. Many manufacturers already have 5 gear gearboxes which they don't want to invest more money to upgrade and some of them don't want to spend money on adding that 6th gear or the additional engineering it will require, so instead of using the ideal gearbox, you get a compromise. You see, the choice of using 5 gears over 6 is largely down to cost. What is the reason then the 3 examples I have listed have such wildly different gearbox characteristics despite having 5 and 6 gears and why the 6th gear doesn't mean anything for your highway driving as is proved in Cruze's case. So, coming back to our ideal engine - gearbox combo, it will have a better spread of power thanks to more gears which can effectively use most of its power band and it will also have a tall overdrive gear for relaxed cruising on highways for good fuel economy, relaxed engine with less noise and wear and tear and less wastage of power (which is the reason for more efficiency and increased fuel economy). Now the more the number of gears, the shorter the gears can be for the initial gears, the closer their ratios will be and thus you can get over the initial dull response of most engines today and quickly move to the meat of the power band. Why more gears? Think of it like a Pizza with more slices for better division, the Pizza is your engine's power and the more the slices or gears the better it can be spread.Īs most of you would know, Internal combustion engines don't have a flat torque curve and gears were used for this exact purpose, the engine can't directly run your car from standstill so the lower gears multiply its torque at the expense of speed, so your engine for example spins 3 times but the tyre spins just 1 time in its first gear thus increasing the effective torque. An optimal gearbox will have a great compromise between acceleration and fuel economy, which means it should ideally have about 6 or more gears. The thing is no matter what the engine, there are optimal gear ratios for extracting the most out of it. Now what do these 3 examples mean? Is it getting even more confusing and pointless? Let me explain. Lets take another example, the previous generation Toyota Innova which would scream its lungs out post 100 KM/h in its 5th gear with many people rightfully wishing for a higher gear. The Cruze even with 5 gears never felt the need for a 6th gear on the highway infact its 5th gear was so long that you got useable acceleration post 120 Km/h at which point it was doing just 2000 RPM.Ĭreta even with its 6 gears, in 6th gear the engine is spinning at 2100 RPM at 100 Km/h with the engine alive and a little too eager, I have always felt a need for a higher gear in Creta when doing speeds above 100 despite it offering a 6 gear transmission simply because its gears are too short. My Chevrolet Cruze had 5 gears and my Creta on the other hand has 6 gears, ignoring the difference in their power output and engine characteristics for a moment (you can hardly get an Apples for Apples example in these cases anyways). Let me take an example to explain it better: The bottom line is it is strictly on case by case basis in each car/bike and it is strictly at the manufacturer's discretion to implement it as they wish to. The fact of the matter is 5th, 6th gear or even higher gears, having them or lack of, have nothing to do with how relaxed your car feels at highway speeds or its acceleration or top speed. This is mainly a FYI or public interest thread for confusion in minds of millions of car enthusiasts and journalists alike, many a times I have heard/read from even senior BHPians and industry veterans in car magazines about lack of 6th gear, gear ratios or absolute lack in knowledge about the same so I'am trying to simplify the facts so that they reach more and more people to clear their confusions. BHPian Rocketscience recently shared this with other enthusiasts.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |