richardsayzz

well my car has about 10k miles and my cars been getting crappy mpg.....i slapped on a k&n filter hoping it would help but it didnt really do much...cruising down PCH at night i was getting only 24mpg....before i used to get like 30......anyone got an idea as to why? searching through the forums may it be i have a fouled maf ??

white_w203

u'll get better gas mileage if you do hwy driving and keeping the rpm's below 3500....maybe even 3k.

richardsayzz

i was cruising at like 60mph and for sure i was keeping the rpms below 3500.... normal streeet driving like a grandma (2800rpm shifts) i get 20-21mpg

mick1

that doesn't sound right because I'm getting 21 mpg with my C320. You should get much better gas mileage.

Sanny

i get 28-29 driving up to west la from garden grove.

if im just around the oc 21 max. but i do have the 2.5 v6

morph860

I seem to get real bad gas mileage when my climate control is on AUTO. I prob get about 19 when its on, i have a c230 coupe....usually run 91 octane

mleskovar

Take it in under warranty. Tell them the power seems down and it's burning more gas than it used to. You can guess with parts but something like this is best diagnosed with Star and known values. Be aware though if it is the MAF they may blame it on the K&N so put the standard one back in before you take it in.

SeaCoupe

I have a 02 C230K. I get about 27 mpg on the fwy, and about 21 mpg around town. I always use 91 octane gas. I did notice that my milage went down a bit when I upgraded ot the 17 inch wheels from stock.

k_lundquist

I heard that in cars that use boost, Granny Shifting isn't always the best way to get the most MPG. Then again this could be my buddy blowing smoke up my a$$. Can anyone confirm?

I shift around 3k and I seem to get decent gas milage... 25-26 city, 32-33 highway. On a long trip cruising at 75 (3000 RPM) I was able to get 36 MPG.

Justinius7

keep it on "C" or "W" makes a HUGE difference.. even on straight freeway...

c-coupe... with AC OFF... 23mpg in "S" with AC OFF... and in "W" or "C" 28mpg...

note, this is straight freeway, on the same day one evening with cruise set at 69 miles per hour on a trip to san fran from LA on the I5... nothing changed except i pushed RESET every hour to see the differences.

Outland

Granny shifting is always the best way to get the most mpg. Once you spool up the boost, a LOT more fuel gets added.


ALWAYS, when not accellerating, keep the rpms as low as possible without lugging the engine. Sometimes, this can be as low as 1500rpm, cruising a slow road. If youre not accellerating, or you can see youre going to stop sometime ahead...let off the damn gas. Three things that affect fuel consumption you can control-

1.the angle of the throttle...the less you press, the less fuel the computer adds.
2.the rotational speed of the engine- the fewer revolutions it has to complete, the fewer times it has to fuel each jug.
3. How long the engine runs when the car isn't moving. Sounds simple, right? Don't sit in the parking lot or the driveway with the engine running, etc...

I can get as much as 34mpg out of my coupe IN the CITY. Sure, I have to take my time, but I'm not holding up traffic, or getting a tow to get that. With very little effort, I can do 29, in the city...the extra 5mpg takes a little more thought. Coast down hills, plan the speed to get thru the next light, changing lanes to maintain speed, etc.

r3v1ls

I drive to Irvine and back to LA practically once a week. My mileage ranges from 25-30 depending on traffic. I don't do any granny shifting, if I'm gonna pass some one I downshift and get the revs up and hit a few turns pretty fast when there's no one around. My RPM's are usually between 2500-3000 depending on how fast i'm cruising which is usually between 70-80. I have a 6speed 02 coupe and run it with 91octane, which by the way makes a huge difference compared to 87 which I used to run. Mileage on the highway increase by about 3-5mpg on the highways with 91 octane in comparison to 87. Hope thise info helps out.

k_lundquist

Good Advice!

richardsayzz

damn im jealous...all of you guys get great mpg....me driving aroud the city at best is like 21-22mpg....18-19 is when i drive normal...i think ima go hitup the stealer see wassup

C43AMG

Has anybody bothered to check their tire pressure ?

drexappeal

Actually, I drive mostly on the street and my MPG is about the same as what you're mentioning (just driving the street). Basically, it translates to 280 total miles (street driving only - which lasts 10 days total of driving, 5 per week). If I drive some on the freeway, some on the streets, my mpg goes up and I'll get anywhere from 320-350 miles total (which usually only lasts for around 7-8 days of driving).

I hope that makes sense.

r3v1ls

Uh getting that at the city is great, don't even bother going to the dealership cause he'll just send you away. We are talking about "highway" mileage which is completely different. It also depends on the city you're in. I live in LA and my mileage in the city is absolute crap, goes from 16-18.

otyaglo

My c240 6-speed does up to 31mpg @ 65mph steady on a 300 mile run @ 2600rpm in 6-th gear

However, my city mileage can go as bad as 10mpg.

Load/AC/rpm - all of it make difference

Keep it ~2600rpm highway is optimal. 2000 in a city is ok
2 passengers and some lugage another 10% less mpg

One question to everybody concerned about fuel economy:
You have heavy expensive German car => should you care what is your mpg?
If you do, buy diesel WV golf or hybrid ...

topekoms

my c240 had really bad mileage a week ago...but after i complained to MB at service, it changed everything. Before i had the car fixed, the car ran 300km with 1 full tank.
after i changed the spark plugs and the spark plug wires, AND making the tires have the right pressure, everything changed!
a full tank now ran 400km! well not exactly but close enough
if u want better mileage
1. stay below 3000rpm because v6 engines drink gas
2. dont do sudden revs
3. dont let the car idle too long
4. check tire pressure
5. get new and good spark plugs. new ones aint that expensive! just that we have to get 2 more than c230k people!
6. bring ur car to service and have everything checked up!
7. dont tailgate. gas +brake then gas and brake again....just wasting gas!
keep the AC off if u wana save more gas and open all the windows! or just the rear 2! if u hate the wind noises then just open the sunroof!
hehe thats jsut a lil advice from me since doing the above helped me get a better mileage!

rrpnow

what type of spark plugs did you get? OEM or aftermarket? if aftermarket, which ones and how much?

advans

I just finished my tank of gas today where the computer says the left over gas has 4 miles range, and I filled up 15.4 gallons and used 166 miles...mostly city and a lil highway

rrpnow

166 miles? thats it? something is def wrong then... thats like ~10 or ~11 mpg... get that checked out


i took ur advice, and today i got 24.4 mpg on the way home... im gonna stop tailgating and fast accelerations..

advans

im doing 100% new york city so no speeds over 45-50mph

and i was bustin chops lately with the tiptronic =T

usually with a little tiptronic and alota normal "D" I get abt 12.7mpg city, city/hwy mix is abt 16mpg-18mpg MAX

MBNorCal

i get 16-17 mpg.

even motortrend and car and driver gets the same when they tested the c350 manual. oh well.

dgwee

Other fuel saving hints include:

1. Reduce unnecessary loads, both inside (remove unused things from trunk) and outside the vehicle (roof racks, etc);

2. Plan your route to avoid traffic, and travel when traffic is light;

3. Practice defensive driving by anticipating traffic conditions ahead;

4. Avoid speeding.