What Gear Is For What Speed?

[andru123]

Hi,

Is driving on higher gear takes less fuel? If I drive let's say, 90 km/h, should it be 5th or 4th? I got this idea that if engine makes less rpm(and it does on higher gears), it eats less benzine.

I just started driving on the highway, since gettin my licence. Sometimes I approach a traffic jam at 125 km/h, and slow down to 50 km/h. Should I switch to 3rd or to 4th? Or continue on 5th is fine?

[deagle]

Hi,

Is driving on higher gear takes less fuel? If I drive let's say, 90 km/h, should it be 5th or 4th? I got this idea that if engine makes less rpm(and it does on higher gears), it eats less benzine.

I just started driving on the highway, since gettin my licence. Sometimes I approach a traffic jam at 125 km/h, and slow down to 50 km/h. Should I switch to 3rd or to 4th? Or continue on 5th is fine?

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Continue on in 5th until you hear a loud bang !

.... Seriously. lower RPM gemerally means less engine cycles and generally better fuel consumption. At 90Kph (around 60mph) you really should be in 5th....

[Ryan1985]

Yeah, at 90kmh you should be in 5th gear but don't let your engine 'labour', thats when you start to lower the mpg!

[Crisis]

Thats not entirly true.

Although using high gears keeps the MPG up, its also about when you change gear, change to late (ie revs to high) and that uses more petrol. Change gear early say 2k RPM and your chocking the engine, which uses up more fuel.

They talked about it on Top Gear a month or so ago.

[alanbradley]

Are you not supposed to try and keep the engine running at about peak torque for the lowest fuel consumption? For us diesel drivers that means trying to keep between 2,200 and 2,800 rpm - not really a hardship.

I don't think that that holds true for petrol as I used to find that if I managed to keep the motor below about 3,250 then the fuel consimption was lower, but overtaking was impossible and it surely wasn't peak torque...

Does that make sense?

Cheers,

Alan

[deagle]

Are you not supposed to try and keep the engine running at about peak torque for the lowest fuel consumption? For us diesel drivers that means trying to keep between 2,200 and 2,800 rpm - not really a hardship.

I don't think that that holds true for petrol as I used to find that if I managed to keep the motor below about 3,250 then the fuel consimption was lower, but overtaking was impossible and it surely wasn't peak torque...

Does that make sense?

Cheers,

Alan

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The Yaris diesel is a superb engine. I regularly get 65mpg without much trouble, but the chap at the link below managed an average of 116mpg.

http://www.carpages.co.uk/toyota/toyota_tw...&echo=677670675

I think that he probably put the car into neutral when going down hills as this can save fuel.

Deagle

[tim220171]

Dont worry to much so long as you are not constantly revving the hell out of it and keep changing gears all the time . dont worry

In town , your mpg will be higher because you change gears alot and are accelerating more often. On the motorway you can cruise gently at 70 - 75 mph , keep the revs constant and speed constant , In fact when you are on the motorway , to keep a constant speed , you will be able to lift off the throttle slightly . You will do more mpg like that on a long journey . Which Yaris do you have ? Even if you have the t sport you can get a good 40 odd to the gallon on that no problem !

[alanbradley]

116mpg!

I have to stop driving with such a lead foot - from February to September and 16,000 miles I thought I'd done well to average 56mpg...

Great car though, and nippy too

A

[Red Yaris 54]

Yaris MMT = Optimum gear for engine revs and good fuel economy as the engine is never allowed to labour or overrev.

[vikasshah]

i've done 4000 miles in a 1.3 t spirit driving on the a406 (london)...can only get 40mpg tops....i put it down to all the idling in traffic....or am i doing something seriously wrong?

2nd at 10-15 mph

3rd about 20-25 mph

4th about 30-35 mph

5th over 40......

not revving it too much but not changing at too low a rev either.

[seveer unaek]

Leave 3rd to 30mph, 4th at 40mph and 5th after 50mph. Unless you're just rolling along the road, in which case get it into 5th asap, but as soon as you need to accelerate.. drop it a gear or two and shift yourself with some revs... the Yaris engine seems to like them!

A simple test to see if you're in too higher gear is when you're driving around, plant your foot, and if there is no urge, or a slight get-up-and-go then you're in too higher a gear. This applies for 1.3 and 1.5 id imagine... nit sure if 1.0 as much urge in the firt place (no offense... just no experience of it!)

[alanbradley]

The 1.0 really needs to be at at least 3250rpm before any serious acceleration is attempted (overtaking and suchlike).

The same test should work! :)

A

[earpl]

1st gear about 6250rpm! iset my first car alarm off at that today!!

[Viper_7]

Gears matter sure.

how fast you acclerate matters..sure... however sometimes it's better to get upto speed quickly rather than get there slowly...ie get into a higher gear as soon as possible..this is especially true for Diesel Engines..especially those with Turbos.

Most importantly for using less fuel is to antipate what's ahead...and keep ya foot off the brake...if you brake..then you've wasted fuel. Ie coming up to lights on red...don't drive up to them...then hit the breaks... anticpate....coast up to em... and you'll find there on green when you get there.. etc etc etc

If in heavy traffic don't drive up the butt of the guy in front..ie the domino effect that causing jams in the first place..guy in front brakes...guy behind brakes harder...as does the guy behind him...until someone stops..then everyone stops behind...you see it all the time on motorways... all this braking burns fuel..

Vipes

[Blue84]

i've done 4000 miles in a 1.3 t spirit driving on the a406 (london)...can only get 40mpg tops....i put it down to all the idling in traffic....or am i doing something seriously wrong?

2nd at 10-15 mph

3rd about 20-25 mph

4th about 30-35 mph

5th over 40......

not revving it too much but not changing at too low a rev either.

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I do the same (roughly) in my 04 1.0L Yaris..although I leave 5th until 50 mph or over and she definately seems to prefer going into 5th at over 50 mph.

[seveer unaek]

I know a really simple test for deciding what revs you should be running at to achieve optimum mpg. Obviously, other than driving with foot on clutch, the best mpg figures are acheived in 5th gear at 50-55mph... correct? Well, have a look what rev's you're running at and voila... that's the revs yous should be in in all gears when speeds are prior to 50mph!

[s0cks]

In new engines, if you engine break it uses no fuel. Try and keep it in a gera where its just above idle revs (i.e 1200-1500) and you should be ok. I can quite happily tootle (is that a word?) along in 5th at 30mph.

For granny driving I changed to 2nd as soon as i pulled away (i.e. 5-10mph). I then changed to 3rd at 15mph, 4th at 20mph, and 5th at 30mph.

[Blue84]

In new engines, if you engine break it uses no fuel. Try and keep it in a gera where its just above idle revs (i.e 1200-1500) and you should be ok. I can quite happily tootle (is that a word?) along in 5th at 30mph.

For granny driving I changed to 2nd as soon as i pulled away (i.e. 5-10mph). I then changed to 3rd at 15mph, 4th at 20mph, and 5th at 30mph.

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I find that my 1.0L doesnt like 5th at 30 mph..she moves but seems to labour a lot..any speed over 40 mph is more liked by her for 5th gear though :)

[reece]

For maximum fuel economy I stay in neutral with the engine turned off

[seveer unaek]

For maximum fuel economy I stay in neutral with the engine turned off

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Kind of negates the point of a car though!

[vmail]

damm, Im getting 20MPG (average)

[seveer unaek]

That's because of the immense speed you're developing in a 1.3!

[vmail]

Only because I dont want to be on the Motorway for 2hrs

[Chappers]

damm, Im getting 20MPG (average)

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<_< Most Mr2 Turb's average more than that..

[seveer unaek]

Only because I dont want to be on the Motorway for 2hrs

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Good point! If there's a nicer route, i'd take it any day over a motorway! Even if it was an hour longer i'd take it... so long as i wasn't in a rush!