ajm0824

Just had 1 yr service performed. Not sure if it's cause but since I got the car back, I'm average about 15-18mpg> Prior I was at 20-23mpg.

Driving habbits the same?

Any ideas if any part of the service could be to blame?

Thanks

X72

Check the air pressure in your tires, ajm0824. They may have lowered the pressure when they serviced your car. I run my tires at 34 psi (cold tire inflation) which is above the MB recommendation (Disclaimer: do this at your own risk). The ride is a bit firmer but my fuel economy is quite good. Get an accurate tire pressure gauge. I use a bicycle pump to inflate the tires when cold (before driving in the morning).
William
2003 E320

X72

By the way, I learned this by listening to the National Public Radio program Car Talk. A woman called in saying that her mileage was much better after having her car serviced at a quick lube place. Tom and Ray thought the explanation was that they inflated her tires when they changed the oil.
William
2003 E320

guitarplayer

Tires never get cold in .......... Miami, do they???? LOL I'll show you some cold tires in about 3 months!

CE750

I love the Tapper brothers! I never miss a show.. You never get MB callers though! A lot of Suburu types.

I run my tires at 38 psi... I find the recommended 29psi too low for my liking. No premature inside tread wear signs yet.. but great milage (more than the EPA rating).

ajm0824

Thanks guys... That actually dawned on me late last night and this morning I checked em.. bout 32psi around.

I'm running 40 profile in front 35 profile tires in rear. Shouldn't the pressure be higher than 32?

thx again

pa28pilot

There is another possibility. If your dealer doesn't use the highest end 229.5 engine oils, you can see somewhere on the order of 1-3% mileage differences. I just went through a whole rigamarole trying to find out exactly which Mobil oil my dealer used after seeing the receipt from a service visit.

HELL ONA HARLEY

I'm thinking your dealer cleared the milage / hours and your average MPG in one menu and your looking at the MPG in the "after start" menu????

CE750

I did too.... the fools weren't even using a Diesel oil.. just the same stuff they put in their gassers.. I now bring in my own jug of Delvac.

HELL ONA HARLEY

ajm0824 is showing a 25% drop in his M.P.G..... There is no way this is oil viscosity / brand related or is it air presure related.....

HELL ONA HARLEY

Wow Sam.... over a thousand posts in less than 2 months!!!!!
You have a lot to say.

CE750

I'm aiming at Ricky's count by sumer next year..

I never thought these forums could be so fun.. it's down right addicting..

HELL ONA HARLEY

How true... I only wish my ol'lady thought as we do...

CE750

You too, ha? coming hunny..

HELL ONA HARLEY

L.O.L....... I try to explain to her that there is no diff between her on her *** reading a mag and I sitting at the desk reading here.... Only my venue of info is always changing hourly and her's monthly.... Seems to do no good though.

CE750

Amen! She says... "it's only a car" but then she spends hours on her "scrap booking" website!

can't win!

CE750

BTW... on the topic... for what it's worth I had the dealer pump up my tires with Nitrogen (life time for $35).. basically a placebo maybe, but I'm told the pressure stays constant better, and there's less moisture to corrode the wheels (like I care).

In aviation, we use No, so I figured it couldn't hurt especially with the temps of the roads here!

HELL ONA HARLEY

Its a placebo for sure in my opinion..... but $35.00 !!!!

Here's a thread I dug up on the subject.

https://mbworld.org/forums/showthrea...light=nitrogen

ajm0824

Just adjusted my tire pressure

Now:

Front: 18 x 8.5: 40 PSI
Rear: 18 x 9.0: 38 PSI

Drove round for bout 45 min (mostly city driving)
Looks slightly better mpg and no noticable loss in ride yet.
bout 19 mpg

I noticed on the receipt they listed part num & desc... gotta check to see if detail of what oil they used.


Regarding those counters.. I've always really just used the After Start one (mostly) but still not entirely sure exactly when it resets... sometimes it keeps going through several starts and sometimes it resets.... but the readings i've been taking to compare is from the after start when at least 1 hr of data has registered. my origional concern was that after couple hrs of normal driving yesterday it registered 13.5 mpg


Another thing I did when I first noticed was slitghly lower was to switch to comfort mode from sport (supposed to start in 2nd vs 1st, if i recall correctly) & I thought it would get better but instead it got worse.. I though that was funny

so back in sport mode, higher PSI on the tires and i'm back up to 19 mpg.


You guys think a fuel injector cleaner would help? I origionally suspected a problem with the gas as I recently filled it up, but then figured if it was watered down I would hear some knocking or something...

thanks for your help.

CE750

thanks.. just read it... sounds like it's worth the $35.. when you consider a breakfast for two at Denny's these days is close to that with tax and tip!

I'm mainly interested in the longer time the No will stay at pressure due to lower leak rate. I just hate going to the air pump getting my fingers filled with brake dust then touch the steering wheel and shifter with those same hands!

BTW.. this is anecdotal, but I put 38psi in my tires two months ago, and thru this hot sumer I'm still at 38psi.. not bad.

CE750

That's pretty darn good for an E320... I only get about 25-26 on a CDI!

Miguk_Saram

Eek!! 25-26 on a CDI!? ..Dude, that hurts!

Just this Saturday I averaged 26.3 mpg on my e500, as per the trip computer (approx. 270 miles rt on a little under half a tank of fuel)!! And that's a v8!

CE750

just to be clear... that's my "average" since reset that I do on every fillup... and I dive 75% in town... stop and go, heavy acceleration (I can't resist ) etc.. On long freeway rides.. I'm getting 37-39mpg.

JimPurdy

Mileage? I took a 600 mile trip over the holiday and got better than 31 mpg. Yesterday, on the return, the trip computer registered 277 miles @ 33.0 mpg. I filled up and calculated 32.25 mpg. Not bad mileage with the outside temperature at 97 degrees f.

Miguk_Saram

Ah.. THAT sounds more like it!

(and now, back to my measly 26.3 mpg... )