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My car scares me while changing gear from 4th to 5th gear because it goes to 3rd gear. As a result on highways i get scared to change to 5th gear.

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Can i drive my car in 4th gear at speed range between 100km to 115km ?

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    aside to the question, it sounds like there is something wrong with your shift linkage. Have it looked at / adjusted. What is the rpm at 115 in 4th gear? – agentp Aug 15 '17 at 14:40
  • In 4th gear the RPM is in between 3000 to less then 4000. – YumYumYum Aug 16 '17 at 6:04
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Yes you could, but it will cruise happier in 5th...

EDIT: (reference)

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  • Thanks, i would never drive in 5th then. it scares me to death in highway when changing 4th to 5th brings me to 3rd in 120km speed highways. – YumYumYum Aug 9 '17 at 6:14
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    You have to concentrate - mine has 6 forward so have to be really careful as they are close together... – Solar Mike Aug 9 '17 at 6:21
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    @YumYumYum a relevant edit, but I think you should post it as your own answer and then you get the recognition, so if you do that's fine... And I'll vote for it :) – Solar Mike Aug 9 '17 at 12:26
  • Its OK thank you. Prefer to have 1 good answer so that later no need to search more reference. – YumYumYum Aug 9 '17 at 12:45
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Nothing puts a strain on the engine like forcing it to pull the car in the wrong gear. Too high a gear strains the bottom end of the engine around the crank and con rods. Too low a gear will mean you are revving more than you need to so the top end of the engine around the valves, cams and lifters are working too hard. You need to troubleshoot why your car goes back to 3rd gear when you engage 5th gear.

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    That table isn't very helpful, as the speeds will be different for every make and model of car, depending on the gear ratios fitted... – Nick C Aug 9 '17 at 8:42
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    and also depends on the engine type - some rev higher than others... Diesels tend to have more gears or higher / longer ratios as they don't rev as high as petrols (some petrol car engines can easily exceed 7000rpm) – Solar Mike Aug 9 '17 at 8:49
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    That table also ignores the optimization of shifting 1-2-4 (skipping third gear when your target is 4th) or 1-2-3-5 (skipping fourth gear when your target is 5th). In fact, I remember one time in my old Renault Laguna that I stopped at an intersection, then started in 3rd (forgot to put in 1st). I only realized the error when the car was slow on the uptake, at which point it was too late to shift back down to at least 2nd gear, but with some footwork carefully working the clutch and gas, I was able to get the car to proper speed without too much trouble. I wouldn't do that on purpose, though! – a CVn Aug 9 '17 at 11:56
  • Please see the official reference in another answer. mechanics.stackexchange.com/a/46953/19239 – YumYumYum Aug 9 '17 at 12:15
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    @YumYumYum: Just because you can doesn't mean you should. Your engine is going to be working a lot harder for longer periods than intended if you're cruising at a RPM range that you instead should be shifting at. Instead of avoiding or masking the core issue, you should instead figure out why pushing the shifter all the way to the side and then up somehow shifts you into 3rd instead of 5th. – Ellesedil Aug 11 '17 at 6:11
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Most 5th gears are over-drive, for cruising at lower RPM to get better gas milage. Older, pre-80's, cars did not even have overdrive and the result was simply more fuel burned cruising the highway at 2500 RPM. The engine will not overheat at a modest RPM under the little load needed to simply maintain legal driving speeds. Many pickup truck automatics have a no-overdrive setting "tow" mode allowing intentional driving without overdrive. Botton line: If the car is not getting hot, you're ok. However, a faulty gear selector is hazardous; you could find your transmission locked up during a shift.

  • Or 6th gears.... – Solar Mike Aug 14 '17 at 8:09
  • I suppose it would apply to the top gear of any common post 70's transmission. From the question, I had to assume they have a common 5 speed. – SteveScottAz Aug 14 '17 at 17:02
  • My 5th is in the same position as theirs most likely right and up. – Solar Mike Aug 14 '17 at 17:04

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