aerodragon

In general, how can I have better MPG?

my car is C320..

dswildfire

use minimal throttle, upshift as early as possible, find the sweet spots for mileage. make sure tires are overinflated, but not excessively. 32F/36R works best for me. no racing

aerodragon

thanks..

i was wondering what's exactly up and downshift?
i was reading somewhere else:
upshift to accelerate (does this refer to reducing the gear number from e.g., 4 to 3?; if so, why is it called up shift?

Jens C320

Upshifting is the opposite...it is shifting into 4th instead of 3rd...here is an example (I am not sure of the gear ratios in the manual though, so just guessing). You are crusing around town, not accelerating and not going up a hill at 35mph, you can use 5th (maybe even 6th) gear instead of 4th or 3rd. This will save gas. Shifting into the highest number gear possible without making the engine sound horrible is one way of improving your gas mileage...but from personal experience, accelerating from traffic lights is the biggest factor in your gas mileage.

aerodragon

i guess i am still confused, it's mentioned here that downshift is to accelerate faster (isn't that upshift?)



'acceleration out of a corner", means when you are turning or on a winding path, you downshift to get that extra torque so that when you are through the turn or winding path, you can accelerate faster. without downshifting, thus you are still in a higher gear, the car is sluggish in accelerating.

Jens C320

No, upshifting is when you shift from a lowered number gear to a higher numbered gear, i.e. shifting from 2nd to 3rd. Downshifting is the opposite, shifting from 3rd into 2nd. And yes, downshifting will get you better acceleration but worse gas mileage.

jpb5151

If we just take it easy and tool around, our 230k gets better mileage. The transmission starts upshifting sooner by itself, and the ride's nice and smooth. The thing about accelerating from a stop being the biggest gas guzzler is definitely the case over here too. Smooth starts give us better mileage, no question. Of course, once the gar gets up to speed, it doesn't slurp much gasoline.

avlis

Turn off the A/C, use cruise control, use the proper grade fuel.

moomeh

since i'm the one being quoted above, i'll elaborate some more. the car starts in 1st gear. then as you start to move, it shifts UP to 2nd and as you get to higher speeds it goes to 3rd, 4th etc. so, what happens is, when you slow down, the car makes proper gear adjustment by DOWN shifting to a lower gear which will allow you to move if you decide to press the gas pedal again, to get you moving.

e.g., if you start out in 3rd gear, the car wouldn't move (or maybe it will, but very very slowly)


so, if you are on the highway, you want to UP shift since you are probably not going to stop and then go stop and go etc. the car will UP shift to the highest gear that it can to conserve fuel and let the car continue to move.


now here is something to think about. let say a winding street is ahead. instead of braking, i DOWn shift to slow down. why? the engine revs up to high levels that has to do with physics, but at the end of winding street, when you apply the gas at that lower gear you DOWN shifted to, you'll accelerate faster. try it.


the best thing about touchshift is that it allows you to shift within a second to the different gears and stops you from shifting to gears that can potentially make your engine explode. so go try it and have fun.

mleskovar

What kind of mileage are you getting? My C320 averaged 25.9 mpg for the last 3500 miles according to the on board computer. I've averaged over 30 mpg on some road trips, unless I cruise at 80 mph+, then it drops to 27 mpg. Around town it averages 21 mpg.

aerodragon

hi,
i think mine averages out 20.5 or so mpg (which is very low I think). i drive cityroads most of the time and sometimes highway driving. how can you get that high?

bagwell

my C320 averages 20.5 to 21 mpg as well

mleskovar

I believe driving style has the biggest affect on fuel economy (and brake/tire/engine life). I don't do jackrabbit starts and rarely does the transmission kick down when passing. Most of my driving is on flat freeways as well and I use cruise control whenever possible. I do not drive slow at all...but most of the time the accelerator is in its first third of travel rather than the last two thirds. What does your computer report as your average mph?

moomeh

mine is 23 city, and 25 highway.

moomeh

i jackrabbit every stop. i downshift a lot too. still, i'm getting good mpg.

MB-BOB

I drive a 17 mile commute daily to work, about equal highway and city driving. My average "After Reset" speed is about 30-32 mph per tankful.

My C320 (21,000 miles) is currently getting 24 mpg. To do this, I turn off the A/C, leave the blower on automatic, lower the RR window about 5 inches and tilt the sunroof up. This creates a nice breeze in the morning. If the afternoon ambient gets above 85 degrees, I'll use the A/C. I can do this, because the humidity isn't that high here in north Texas. IMO, using the A/C cuts your tank to tank mileage by a good 2 MPG.

I don't drive aggressively, but my rear tires are nearly shot in just two years, so I don't drive like a granny, either.

Another factor is the odometer reading on the car. I noticed the mileage improving for the first 15,000 miles... It wasn't very good at all when new. If the car is new, be patient.

jpb5151

MB-BOB, how much does the AC affect your gas mileage? I'm just curious.

mrkrichie

I am only getting about 19.5mpg on my c240. My avg speed is 23mph. Is this about right?

MB-BOB

Re-read.. Second paragraph, last sentence...

jpb5151

Thanks, missed it, must've been distracted or something, feel extremely stupid right about now...

This week we've been running the AC quite a bit. So far, I've seen about a 3 mpg drop according to the display. Need more time to be sure about that number. Our car's got the 1.8L engine.

mleskovar

I leave HAC on auto constantly. I believe AC would affect mpg more with 230 and 240.

Outland

I thought it would to, but it doesn't make as much a difference as how you drive does.

Keeping the computer screen that displays mileage after start up all the time is great way to keep the mileage up, when you see it dip, grab a higher gear or get off the gas.

Using a combination of cruise control, coasting down the hills, no AC, light throttle and lots of tall gears, Ive gotten over 40mpg on my ride home from work a few times now. Best Ive ever gotten in 'normal' driving is 34. With my mostly city driving loop, the car is averaging 25.5mpg. Not bad.

blueC230K

Right now my car hits 20k Miles....just pour Valvoline Fuel treatment system(put it every 10k, and use the cleaning ones for every 3k)----it has improved 5MPG....I guess this helps a little