revs

[tinkybeard]

hi all ive bib driving my c220 cdi around keeping the reves under 2000 trying to get good mpg does anyone know what the most effient revs would be
thats all and has any one washed there car enough to go though the paint as my wife says im about to do just that

 

[Ron Palfrey]

I take it that it is a manual, not auto? Your approach seems to verge on the obsessive.
Just accelerate gently, drive smoothly, and think ahead so that you don't need to use the brakes too much. Leave a decent gap between the vehicle in front.

I wash my cars every 6 months, whether they need it or not. Still got plenty of paint on them.

 

[s999sws]

I never wash my car, the dirt and dust protect it from the sun's rays. Anyway, that's what I tell my wife!

 

[jberks]

scrubbed the hell out of mine - still plenty of paint. Lots of wax too.
Throttle and how smoothly you operate it seems to have the greatest effect on fuel economy I find. Revs seem almost irrelevant though clearly the lower the better. They key to good economy - aside from avoiding jams, is anticipation, trying to use the brakes as little as possible. This can make 10-20% difference easily.

 

[rf065]

hi all ive bib driving my c220 cdi around keeping the reves under 2000 trying to get good mpg does anyone know what the most effient revs would be
thats all and has any one washed there car enough to go though the paint as my wife says im about to do just that

I always thought the most efficient amount of revs corresponded to the peak torque. i.e., if peak torque is at 2000 rpm, that will be the most fuel efficient speed to run the engine at.
Gentle acceleration and avoiding using the brakes is what really makes the difference though, you really need to read the road far ahead of you.

Russ

 

[kdned]

At 2000 rpm - the engine is not at its most efficent but you should still be getting mid 30's running round town etc - Use the cruise control as much as and whenever possible - ie: on motorways set it at approx 2500 rpm - depending on distance you should get as much as 50 + mpg - I get this on a daily basis - does approx 550 - 600 miles between fuel warning lights.

 

[tinkybeard]

thanks alot i will try 2500rpm im getting about 40 i think but thats not bad

 

[jpbp200]

constant 56mph in top gear is the most efficent, however, turning the aircon off (if you have it) will save you 20% maybe more, although leaving it off for prolonged periods is not good for it. It likes to be used and what you might save in fuel will be wasted on aircon service! Careful driving is the key, consider looking at advanced driving techniques. Imagine you have a washing up bowl on the bonnet with a ping pong ball in it. The idea is not to let the ball come out of the bowl. Aim for that kind of driving and you won't go far wrong. BTW you can drive around a race track on that principle so it doesn't mean you have to drive slowly, just smoothly..... Also, look up the definifition of efficent for more ideas.

 

[television]

On fuel economy runs they get the car into top as soon as possible, way up the road ahead and go on from there

 

[rf065]

thanks alot i will try 2500rpm im getting about 40 i think but thats not bad

Peak torque for the 220CDi is quoted at 2000rpm. This is where the engine is most efficient. Even if the torque curve is flat and the same torque figure is available at 2500rpm, you will be going faster and have more wind resistance.
You have to balance all of this with how badly you want to get max mpg and how many angry motorists you want trying to pass you.

Cruise control will use more fuel as it cannot think ahead and will only use more fuel everytime you hit an incline to keep the same speed.


Russ

 

[Parrot of Doom]

My sister used to do this, always changing gear as soon as possible. She probably still does.

I tried to explain by asking her if she would ride a bicycle in the same way, of course going uphill you choose the easiest gear to get the best cadence, you don't always select the smallest ring.