Dredd

I just finished my first tank of gas in the car. The previous owner had it filled up when I went to get it last Sunday. Don't know how much he drove it with that tank, because the trip wasn't reset until I started home with it, so I may have gotten better milage than this.

I got 341 miles out of this tank, it was ALMOST on the red at "E" when I refilled. That puts me at 19.83 mpg doing all city driving. That's right on par with what they are supposed to do.

I also don't know what type of gas he put in it. I put mid-grade in it today, and I know the book says "91 octane only", but so does everything.

What do you guys run for gas? How do these things run on cheap 87 octane?

fuzzy02CLS

iTrader: (2)

Actually this car runs better on 91 or 93. Put in the 93 next time. It's already been discussed time & time again. The car's computer will detune the car to run on cheap gas but will get worse fuel economy & performance then if you put in 93. Also the difference between a fill up at 87 compared to 93 is less then $5.
Why? Because the cars engine is high compression. High compression engines need a higher octane fuel. Other cars might get away with it cause they are on the borderline of low/high compression. Not the CLS engine.

Also you calculate by gallons put in then how many miles you drive when you fill up the next time. "341 miles on a tank" means nothing.

ljmushock

I usually fill up right at 14 gal, and thats if I run it all the way to the red line. average mpg yield for me is about 280-300... so right at 20mpg... I also punch it at least a few times for every tank. I think what helps me get good mileage is cruising in 5th and 6th all the time.

black label

I've been able to get as many as 510 out of a tank (and I could have squeezed for more but I chickened out). It worked out to a little over 32mpg.

Mine's a 6MT though and I can do things to squeeze for mileage that would probably damage your tranny. I apparently have geographical/topographical advantageous commute that helps with the MPG's.

jaysizzlecity

Always go with 93 octane........

pits200

Ya, you got better than 19.xx mpg... You made the standard mistake that most people make calculating mpg.

You figured, hey the CL has a 17 gallon tank and I was almost empty.

So 341/17 = about 20mpg but meanwhile you probably didnt put more than 15 gallons in your car.

Maybe I'm wrong but it seems that at 341 miles unless you ran the tank bone dry, you got better than 19.xx mpg.

matpCLTN

I'm running 89 octane, city/highway and getting 460-465 miles on about 14.2 give or take gallons consistent....32mpg in the CL-p

krazykrnboi

wow... u drive on highway 80% of the ti me??? lol

i get 280-317 per tank fill up

fuzzy02CLS

iTrader: (2)

CLP engine is different.

cltypeSLOW

i tried running 93 for about 10 tanks and saw no noticable increase in fuel economy other than standard deviation, so im back running 87 with no loss in milage.

SG81

iTrader: (1)

converted, i get about 370 miles/tank, 60% city driving. just changed my O2 sensor too

SG81

iTrader: (1)

, or 94

rp_guy

i'm at a higher elevation so i can also run 87 without penalty.

YeuEmMaiMai

23/32 here

Oh1TypeS

DRAFTING = MO MPG! 470miles on one tank freeway at 85-95mph, 93octane, CL-S

Dredd

Well that's good to know. I figured it was better than what I came up with. It was a full tank when I got it, so I figured to go off of 17.2/341. I didn't see exactly how many gallons I put in this time, I'll pay attention next time.

NiteQwill

400-450 miles per tank, driving like an old lady. 60/40 hwy/cty

mnd643

450+ MI with my trunk/car loaded up. 32ish MPG. 01 Cl-s 93 octane

SatinSilverAV6

iTrader: (2)

I don't know why you wouldn't use premium fuel. Its only .20 cents more a gallon. 15 gallons is only 3 bucks more. Your car recommends premium for a reason. 91 octane will resist to knocking better than 87 will. Im sure if you dyno'd on 87 you would see a drop in power.

I have used premium fuel in my 03 AV6 5AT since the day it was new. I got 26.2MPG all city driving last time I filled up.

YeuEmMaiMai

where he's at premium is a waste............his compression is not 10.1 to 1 it is more like 9.5 to one once you take the thinner air into account

TheWeez

I've been getting 28mpg mixed driving this summer with plenty of spirited driving.

andyjl

wow u get that much? How much hwy driving do you do, like 95%? I don't get anywhere near that with city/hwy split around evently. I usually fill up at about 250 or so and i get around 20 mpg.

back when i used to drive 50 miles to school and back everyday, like 3 years ago, i could push it up to 420 at the most with i'd say about 95% hwy and even putting it in cruise control at 60mph. averaged around 30 miles a gallon with 91 octane back then. Even tried 87octane every now and then to see any significant differences in miles per gallon with a different octane rating.

now use 87 octane and get around 20-22 mpg with more city driving. I don't think there really is any significant difference in mpg the way i've experienced it.

Oh1TypeS

Update just drove from Detroit to Pa, went an amazing 542 miles on ONE tank of Sunoco ultra 94. 85-95mph WITH AC blazing about half the time. SUV's are good for something (DRAFTING!!!!!!!!)

JohnBlayz142

26mpg city in my car. 91 octane. i've been very happy with my gas mileage.

invisiblewar

wow i only get about 300miles pure city

andyjl

wow, some of you guys are getting a lot more miles than I am. Maybe it has something to do with my oxygen sensor? I haven't been on the boards in a long time, but I remember something about having a good oxygen sensor or changing it once in a while should help increase mpg. I've done a search but couldn't really find anything.

How does one know when to change the o2 sensor, where do you get it changed? at your local mechanic or pep boys? and how much would it cost?

YeuEmMaiMai

keeping the engine at 2K-2.5K during accelleration goes a LONG way to helping city milage

zopert4

'03 CL-S Auto, 91-octane. I'll always be able to make it between San Jose and San Diego, CA (about 475 miles) on one tank of gas, going 90-100 highway most of the trip, weaving, not drafting. By the time I finish the trip, I've always got enough to run a few errands and drive around a little bit before I start feeling like i might need to get gas (usually before the light comes on).

So about 475 miles and at most 17 gallons (full tank estimate, even though i never use the full tnak on the trip).

475 miles / 17 gallons = 27.9 mpg

I'm getting at least 28 mpg with mine :-)

pits200

Many times when I thought I have ran my car to the last drop I still don't end up putting more than 15.5 gallons of gas into my car.

I wonder if anyone has ever even put in over 16 gallons of gas into their car during fill-up?

So every estimate that uses 17 gallons as the standard are not accurately calculating their mileage.

black label

I put 16.7 gallons in once and freaked myself out because I didn't realize how close I was to being completely out of gas.

pits200

Wow 16.7, I am was way below the red line when I put in 15.5 gallons, I cant even imagine how low you must have been.

nbennettksu

iTrader: (2)

same here.

went to VA a few months back and got right over 500mi all hwy

CL-S24

Once I hit 40 miles after the light comes on i fill up. But it's still only around 15.4 to fill up. If i really wanted i could go 60 after the light. 70/30 hwy/city

YeuEmMaiMai

the last 2 weeks have been nothing but city miles and I have driven 330 miles. based upon where the needle is I would say I am about 15 gallons for a fillup

zopert4

any of us using 17 aren't doing it accurately, but as a rough estimate it gives is our base minimum mpg. if we were to use 15-16 gallons (what i assume most of us are really filling up at), we'd actually be calculating a higher mpg. our 17mile estimate is like our absolute minimum average

LIPPSTUH

iTrader: (2)

closest i'be been was 15.8 =\ and i get around 22mpg mixed =[

GuddsCLtypeS

something must be wrong..in the past few weeks ive been concentrating on getting good gas mileage (and for the record i ALWAYS pump 93) and my mileage is well below u guys. ive been making sure to accelerate slowly and cruise in top gear whenever possible. and with pure city driving ive been getting a consistent 240 miles per tank and on my road trip to boston i got 375 miles per tank 95% highway miles.

Ive been meaning to clean or replace my filter in my icebox for awhile now. I bought the car at 30k and its now at 83k and the filter hasnt been touched since i bought it from the dealership, still has the comptech foam filter in it. would that have anything to do with getting such more mileage? and as others have said a new o2 sensor may help i guess..

any suggestions guys?

LIPPSTUH

iTrader: (2)

you throwing any codes?

GuddsCLtypeS

well i own a detailing/autobody/customization and performance shop here in VT but i just recently had to let go my mechanic and he took his scanner with him so i havent had a chance to plug one in for awhile and seeing as ive had no dash lights on i havent really thought to. ill be able to check it when i get to work on monday though and ill see if anything comes up, im probly going to order the K&N replacement filter for my icebox too just cuz my comptech one is nasty. i guess ill check the codes and go from there.

GreenMonster

Yeah, I'm convinced most people don't know how to calculate gas milage...

Black label has a thread documenting the miles and gallons for his 32 mpg on one tank run, so that's believable when compared to people just throwing numbers out there...

https://acurazine.com/forums/car-talk-5/zen-art-long-distance-coasting-393342/

I've got a small notebook documenting every gas fill up I've done on my CL since it was new... So I could tell you what the average gas mileage for the last 75K miles is for my CL (to lazy to add it all up tho). Figures without documentation are worthless IMHO...