gas mileage

[ryhi]

according to this site (http://www.edmunds.com/used/1999/mercedesbenz/cclass/12834/specs.html?tid=edmunds.u.prices.leftsidenav..6.Mer cedes-Benz*) my c230k should be getting 344 miles per full tank. everytime i fill up, i zero my mileage and get an average of about 250 miles per tank... i admit, i drive my car pretty hard, but not THAT hard. i dont think that would decrease my mileage 100 miles per tank! what can be the cause of my bad gas mileage? air filter? fuel filter? someone give me some insight on this please!

[steponit]

hmm thats a pretty bad drop. well my 2000 c230k gets more or less 344 a full tank on the Winter setting on the W/S switch. However when I went over to the S setting, my miles drop per tank (approx. to 300). this could be the cause. what are you driving in?

[ryhi]

im usually in S unless its raining.

[sph17]

anywhere from 22 mpg to 30 mpg depending on how much is highway milage. Filling up my gas tank to the top of the filler neck, I have 15 gal till my low fuel light comes on...so I go anywhere from 330 miles to 450 miles till my low fuel light comes on.

[sorbo]

the problem is in the gas milage figures they give. I lookes at my (c280) original sticker and their numbers were on the higher side.

[vas2vas]

I never get more than 23 combined (city/highway) from my 95 c280.... :(
the 318is is a whole different situation though.... :D

[GDawgC220]

I usually get 350 - 400 mi on my C220. More around 350 most of the time.

I do floor it and drive at higher speeds cuz i'm on the highway most of the time for my commute.

Every quarter section of the gas gauge, I get about 100 mi, give or take a few...so I guess around 25mpg.

Bad 02 sensors and clogged air filters are usually something that causes a drop in gas mileage. I would check out the air filter. Take it out and flex it. Then look through it towards the sun. if you can see light, then it should be fine, but if you can't see any light, then it's more than likely clogged. When was the last time it was changed out?

[unsp0ken]

250 miles per tank? thats pretts pretty low. do you drive mostly city streets or freeway?

[redc36]

thats nothing i am happy if i reach 200 mark from my C36. btw my exhaust smells funny. looks like to much fuel into cat. i tried cleaning air sensor with isorpopyl alcohol now i am changing at least one o2 sensor.

well i was also wondering if my cat is bad will o2 sensor before cat will make a different. will it affect o2 sensor in a negative way?

[GDawgC220]

this tank that i'm on now is kinda strange. I've driven 360 miles already and it's still before the reserve light. It's inbetween the reserve light and the last quarter line :p

I hope my fuel gauge isn't wrong...or it'll be fun running out of gas somewhere, lol.

[kameraguy]

To add more data for comparision sake, I consistently get 305 or 310 miles per tank if I drive my 97 C36 to complete empty with lots of highway miles. But in a mixed city/highway drive with grandpa driving I get about 285 miles to the tank right until the yellow warning light comes on. So factor in a few more miles on top of that.

If I drive my car hard, I get about 265 miles until the yellow warning light comes on.

But yeah, it really depends on how you drive. But dang, 250 vs 344....that's a huge difference!!

[ryhi]

im gonna look into my air filter today.... where can i buy an air filter that would perfectly fit my car? i remember when i changed it before i had to make a cut about half an inch wide on one side just so it would fit in.

[GDawgC220]

Originally posted by ryhi
im gonna look into my air filter today.... where can i buy an air filter that would perfectly fit my car? i remember when i changed it before i had to make a cut about half an inch wide on one side just so it would fit in.

they're available at your local dealer parts counter :D

I think they're like $15 a piece...not much.

Those would fit perfectly inside the airbox, no modding needed, hehe. Just tell them the year and model of your car.

[ryhi]

do fuel filters play a big part in gas mileage? how much do they cost and how hard is it to change?

[jnolte]

i get from 200-220

i got the 4.3 litro tho

what do other c43 owners get, i feel like im constantly filling up and with gas prices like this, im going bankrupt fast!!

[Rocky]

Originally posted by ryhi
do fuel filters play a big part in gas mileage? how much do they cost and how hard is it to change?

Yeah they do. I had a 6 year old fuel filter and i was getting GREAT gas milage. Once I changed it..milage dropped but the car felt sooooo much better. More power and smoother.

Decreasing gas Milage is a good sign of a fulty O2 sensor as well.

[sorbo]

just did some math and for the past two tanks i am filling up @ 310 miles (a little shy of the reserve light) and it is right around 24 mpg (94 280) mainly city driving (85%) BUT I DONT USE THE AC!! that is the biggest improvement for city driving. for highway use the ac.

[Denlasoul]

I get probably close to 400 on a tank.

I usually fill around 300-350, most of the time my indicator is still not triggered.

[jnolte]

Originally posted by Denlasoul
I get probably close to 400 on a tank.

I usually fill around 300-350, most of the time my indicator is still not triggered.

how the hell do you get 400 and u got a 4.3 liter v8?

i can barly get 220 and i dont drive that fast anymore, im a old man style driver!!!

something must be wrong with my car

[jlomon]

The best I've ever seen on my 94 C280 was 27 mpg and that was pure highway driving, filling up the car before getting on the highway and driving it straight to the next fuel stop. I averaged about 70-75 mph on the trip.

Jonathan

[Tump43]

I'm with jnolte -- I get between 230 and 260 miles per tank; I usually fill up just at or before reserve so that means 240 miles per 14 gallons. When I kept track of this I was getting between 17 and 19 mpg on average with 70 % backroad/city driving and 30% highway driving. With highway driving only (measured during my last 800 mile trip) I will get 22 mpg at best. I've never done better.

I do drive like a maniac but, I am fanatic about maintaining the car. Changed the O2 sensors at 60K, the filters every 15 (K&N's I wash) changed the plugs and wires at 60K, change the tranny fluid and filter every 40K, diff fluid every 60K, brake fluid and coolant every year, power steering fluid every two years -- you'd think I'd get better milage, but no.

Now that my gas gauage is acting up I have to convince the stealer to replace my gas level sending units purs. to warranty. I just read the results of my search on the issue and it seems that failure of the sending unit is common problem. I think the stealer should just replace mine because I notice the reserve light flashing on four occasions when the tank is full and the gas cap is tight and once, the gauge read empty and the reserve light came on when it still has almost 1/2 a tank. The dealer replaced the gas "shut off valve" but didn't want to replace the senders.

How do I convince him to replace the fuel level senders? Any tricks or suggestions would be appreciated. My warranty (that I have thoroughly used, much to the dealer's chagrin) expires this January.

Thanks,