Buellwinkle

Zero rpm will give you the maximum economy.

yeuchau

29mpg is very good on c320 already, don't think its possible to get 35mpg on C320

benzito911

if ya really gettin 35 thats amazing!! take it to the stealer ant let them know that ur getting more than you should. so they can tell us what to do, the best i gotten is 31mpg and thats with a few mods that are suppose to help me with my mpg, maybe i need a tune-up, but thats crazyness!!

04C320

I've been trying the last week or so to maximize my MPG and got the following:

Setting cruise at 70 MPH got me 23+ MPG (A/C set about half way)
No cruise and staying between 70-75 (mostly 75) got me 25+ MPG (A/C set about half way)

and just this morning I got 28+ staying a constant 75 MPH A/C OFF.

I live and travel in central Massachusetts with rolling hills and valley's. I've found with seting cruise it doesn't allow to "coast" down the hills.
I travel 25+ miles one way to work, mostly highway. I just made a trip to and from Boston which is 54 miles one way. On the way in I got 27+ MPG with an average highway speed of 75 MPH and 25+ MPG on the way home averaging closer to 80 MPH.

I have an '04 C320 4matic.

Oluedo

Try experimenting with 65 - 70mph if possible and let me know what you get. I almost pulled 30 today to work.

benzito911

alpinweiss

Well yes, I hadn't thought of that.

Next best economy for many engines is at the peak torque rating rpm. I am not sure what that is for the C320, but it should be listed in your owners manual. You may or may not be able to hold this rpm, if you have an automatic transmission.

As stated previously, a C230K (M271) with manual trans. will give you the best economy.

lkfoster

Back in the early '80s BMW published guidelines for maximum fuel economy. Shift points should be less than 2,000 rpm and less than full throttle. What you're trying to do is minimize pumping losses by wider throttle opening and friction losses from high rpms.

The one caveat is that it works on manual transmissions mostly. C or W mode is as close as you're going to be able to get with an automatic.

p_gill

Oluedo,

1. turn off the AC and drive with the window down at speeds under 50 mph

2. choose a route that keeps you moving for the first five minutes (not sure about the 3.2 but the 1.8 kompressor runs rich to light up the cat sooner, the waste of fuel seems to be the worst at idle)

3. travel the same route each day and remember the mpg at a particular point on the route, this will help you understand if you are doing better or worse.

4. accelerate slowly, the people behind you will not be happy!

5. use cruise control as often as possible

6. use the brakes as little as possible.

7. choose the route that keeps speed down but you won't have to stop


The other day going home I got an indicated 35.8 MPG door to door from work to home. This is slightly down hill.

In the morning of that same day coming to work I got 34.0 MPG. This is slightly up hill.

Both of these numbers are from the on board computer.

When I calculate my actual mileage at the end of the week I am expecting 30 to 31 MPG due to some stop and go driving. I will let you know.

@65 MPH on a flat road with no wind I would actually get close to the mid 30's

For reference If I drive like gas is free I get about 24 MPG.


Good Luck

Paul




My car

c230 1.8 Kompressor (6-speed)

amdeutsch

Comparing a 4-cyl to a 6-cyl hardly has merit in this case.

advans

you should watch TOP Gear, Season 4 Episode 4 I believe, where Jeremy Clarkson does a 800 mile drive on 1 tank of gas, in a Audi S8 TDI (I think it is)

1. Driving with the windows down creates more drag, therefore less mpg. best is to drive with, windows closed, AC off, everything else off.

5. Sometimes using cruise control, the car moves at a set RPM range, where the engine keeps pumping the gas in. Controlling the car at a low RPM range, with your foot is the best.

Also, when reaching lights, try to take your time to get there, the car uses basically minimal gas at low speeds cruising, but at a stop light, in Drive or Neutral, the engine pumps in a bit more gas to keep the engine from stalling!

Defiant

Criminy, I'm dying soon enough as it is. No need to pre-experience the phenomenon. I'll pony up the extra $20 instead, thanks.

Oluedo

I will get back to you with my results on a comparable road.

C230 Sport Coup

I'm going to have my local guy set my engine to run on 87 octane and see what happens. Loss of power yes, but *someone* told me (who tried this)
that 37mpg is possible on the M111 4 cylinder.

Defiant

Just drive as though you're afraid you'll damage the engine by using the wrong fuel with too much throttle. You'll see the same gains. And, the agony isn't diminished.

lkfoster

I'm thinking that that's a bit high if you're talking a mix of freeway and around town driving. I'm only getting 32.5 mpg with a 1.4 liter Mk5 VW Golf which weighs a fair bit less than a W203.

04C320

Here's the latest...

Last night on the way home with an average of 70-75 MPH I could only get 26+ MPG. I slowed down a bit this morning on the way in, a steady 70 MPH, and just reached 29 MPG. Also, NO A/C at all on either trip.

While I enjoy the better MPG, I honestly had a hard time staying at or under 70 MPH. On days I have all the time in the world, I'll slow it down but most times I'm running a little late so I get into the gas a bit more.

Rev 2 Liv

[QUOTE=advans;2891660]you should watch TOP Gear, Season 4 Episode 4 I believe, where Jeremy Clarkson does a 800 mile drive on 1 tank of gas, in a Audi S8 TDI (I think it is)

Maybe i'm high maintenance, but I NEED my a/c for Northeast Summers. I'm curious about how convertible owners do with top up vs top down.

I disagree. On long stretches of highway, brain fade will lead to a variance of at least 5 miles at any given time. My commute is 52 miles round trip so i'm very sensitive about mpg and my brain fade. Sometimes i'll stick it at 65-70, other times 75-80. Cruise ensures that i don't float between 65-80,

Agreed! I notice that brake assist makes me brake later when approaching a stop light than in other cars. Therefore i've practiced the art of coasting to idle before hitting the brakes gently.

I need to improve my on ramp/off ramp approach. I try to scrub off as little speed as possible, yet maintain grip/safety at all times. Practice using different lines using as much of the marked road as possible as well as turn in position and turn off.

Also, if necessary, brake gently in a straight line BEFORE entering/exiting a ramp.

Avoid braking during turn in since that will kill your line and scub off too much speed.

ALWAYS leave a large margin of safety out of respect for yourself, family, and fellow motorists.

Ets C320

29 mpg?? That's impossible!!! I get more like 21mpg....

When I go fast, it's worst.... :-)

lkfoster

Hmmm, I get 20-22 mpg normally with a somewhat larger engine. I guess I need to pick up the pace a bit.

Oluedo

Made 30.3mpg to work today. Never got beyond 68mph. I work 28miles away from home so I used less than a gallon to get to work. Sweeeet!

A/C was at 0 (completely off) though and moon roof was open.

*went down from 30.9 to 30.3 at the off ramp and stop lights before work place.

JLD2k3

When my AC broke last year I found that venting the sunroof and some combination of just cracking the rear windows pulled a lot of air in through the door panel cracks. This was a very good way to save some gas and keep a little cooler without adding the drag of running all 4 windows down. Though I don't really buy the drag factor for the windows b/c NASCAR would have windows if it really mattered.

flush

the maximum rpm for fuel economy in any car is ....... 0. don't drive.

p_gill

Oluedo,

It looks like you are making good progress.

Our cars are heavy so anything above 30 mpg is a good achievement.

Not only have you saved quite a bit on gas but you have also proven that your V-6 is running well.

Happy motoring

Paul


PS now if I could only get my wife to get over 20 mpg in her SUV, it get's close to 24 when I drive it

MRK

use 89octane gas..... on a road trip in the middle of nowhere TX I went for the 89 since the 91 was $4.69...about .50 more than in civilization...long story short about 60 miles past the fill up the check engine light came on...I was fairly certain that the gas was the issue...in civilization I filled up with 91 and about 50 mile into that tank the light turned off.....