hey all, i wan to know if i am doing anything wrong or something wrong with my computer in the car...i have 29 MPG since i got my car couple of months ago..i have a 2005 MCSC with no mods done (YET). i;ve been driving normal on highway and normal road...

so today i test it today driving above the speed limit and faster acceleration for extended time..and my car still read 29 MPG...

 

What grade gas are you using?

 

Mine has varied between 21 and 33 in 4 months of 2008 MCSC ownership. I suggest:

Experiment.
Check your average speed.
Reset the OBC at fill-ups (after writing down average speed, average MPG, and gallons at full fill up)
Hand calc your mileage.

 

i always use premium..only the BEST for my baby

 

did you reset the mileage before you did your test? My wife has an explorer that she said got 18mpg for hwy and city...then I investigated and found that the mileage computer had never been reset...so it had averaged 18mpg over 180,000 miles and thus no 200mile 15mpg city drive would change that.

 

yes i did reset it when i do the expermeiment BUT its still read 29 MPG..

 

I had the OBC on my 1st MINI an 03 & it drove me crazy
So when I optioned my Cabrio I decided not to get it. It had the 2 things I was interested in. Temp & MPH. I just calculate my gas mileage in my head.

But given that, if you truly are getting 29 MPG (combo miles) in a S, that is pretty good gas mileage.

Lois

 

I just picked up my '08 MCSC and the sticker says it is rated at 21 City and 29 Highway, so it sounds like you're where you are supposed to be. I'm not paying much attention to what the computer tells me for average mpg...I keep track in a little book...but I do like the OBC for other stuff. I've only had him for 4 days, and most of that was I-90 driving, but I'm sitting at about 32 mpg right now.

 

i thot MPG suppsoed ot go down if u driving faster... mine is unchanged even i was driving fast

 

If you have an iPhone there is a quick little app call MPG that will keep a record for you of mpg, price per gallon, miles per tank, miles driven, dollars spent, gallons pumped. I think it is about 0.99 cents. There is also one called Gas Hog.

 

The key is to skip gas with Ethanol added. Much better MPG that way. Averaging 29mpg with the top down ain't bad, though.

 

i only use permium gas and not sure if there any ethanol in it..

i am happy abt the good gas milaege.. BUT the part that troubling me is thta it does not change even when i drive with a HEAVY foot... btw, what the difference with "avg cons" and "cons" in mpg when i click onbaord computer..? should i sent it in for service?

 

my iphone is not link to the car.. i only use car charger

how does this app work?

 

I think you enter those things manually.

You're actually doing pretty good mileage wise. How much of the time do you drive with the top down? That would make the biggest difference in mileage when you drive faster. On the S, the 6th gear hits the sweet spot of the engine at almost all highway speeds, so driving 10mph faster or slower may not make much difference there. In town, hard launches vs soft ones would make a difference, but not as much as you think. The process of stop and go eats up more gas that the speed difference, so if you drive the same route every day, you're not likely to see a big mpg change based on driving habits. A/C usage, top up/down, what gear you drive in make more of a difference really.

 

I got 32 on my trip to Missouri with the top up and the AC on. That was intentionally avoiding gas with ethanol, or I'm sure I'd have been under 30.

 

Avg cons = average fuel consumption. This calculation can be reset by holding down the OBC selection button for a few seconds. It basically calculates your average fuel economy since the last reset.

cons = instaneous fuel consumption (economy). This value cannot be reset and is a representation of the fuel economy at any given moment in time. It should change constantly and considerably depending on engine load, speed, temperature, etc.

If after resetting your "avg cons" it remains on 29 mpg, then something is wrong. I suspect you have not reset the calculation properly. After selecting "avg cons" then hold down the button for several seconds. If you are not moving, it will show --.- If you are moving it will immediately change to figure matching "cons", before settling down as the consumption is average over time.

 

I average 20 mpg...

 

lol guess you haven't seen the revised EPA ratings. They're supposed to be more accurate. 29 sounds about right. But I guess you could always calculate it to actually see what you're getting.

 

The most important thing to TRY is find gas without ethanol, as mentioned above. It's hard to find in many states.
PREMIUM is your friend, too.

 

I have a non-S and I get 29 MPG average, which is damn good for driving on San Francisco hills and the stop and go traffic. On the highway I get a little better, but the hills in my town kill the average.

So I think for an S you are doing quite well.

 

I average 23.5 mpg, all around town driving which is fairly spirited.

You won't see a fluctuation in quite some time if you haven't reset your MPG calculator.

I would say that 91 octane is fine. In some places you can get 93, like here in PA, but it is unnecessary without some decent mods.

 

Here in Austin, you have a choice of 87, 89, or 93 octane gas. So far, I have been using the 89 with good results. I cannot hear/fell any detonation and the power and fuel economy are just fine. My main concern with going with the 93 octane is that turn-over of stock is slow and therefore I may be paying a premium for old gas. If it was winter, I might be so concerned...

 

my 03 gets 24-30....

 

OK, today I am going water skiing at Lake Shasta, which is a 230 trip down Interstate 5, most of it flat.

Will report back on mileage.

Given the aggressive police coverage of the roads on the way there, will be doing about 72 the whole way, unless it is posted one can do 70 to 75 [it has been awhile since I have been on that road, so I don't know if they still have those "high speed" areas.] If there are high speed areas, I will do about 7 miles over.

Reminder - my car is a non-S.

Bonus Comment - I won't be doin any of that hypermiling nonsense.