Im completely perplexed...

[OtisBlkR1]

explain this to me. I started driving my current DD last summer, it was my wifes car the two years prior to that. Being a BITOG'er of course im prone to paying attention I reset the cars MPG trip computer at every fill up and almost always average 20mpg mixed driving. only on long highway trips have I ever observed 26-29 MPG and clearly that was due to hwy driving. So, last week im checking my tires and notice im down to 14 psi in my RR. It goes to the shop for a fix (valve stem) within a day or so I top up the car and reset the trip computer. Im now averaging 30 MPG constantly and jumping up from 29-32mpg here and there. I know we recently we switched over to summer gas (within the past month I believe) however I cant fathom the car jumping a average of 10mpg from winter to summer gas, and the leaking tire only went maybe 4-5 weeks since I checked it last. Also worth noting I just did a OCI with 7,500 on the Mobil 1 5-20

So im perplexed, cars running great, ive got no complaints at all, I know that im not letting the car run several minutes now v.s. then summer/winter however this just seems like way to big of a jump. I filled up 7 days ago, the car has been driven daily. Nothing has changed. still maintaining average 30 mpg.

Im not complaining. what say you ?

 

[Smoky14]

Don't look the gift horse in the mouth, just ride it in good health.
Smoky

 

[Hokiefyd]

Originally Posted By: OtisBlkR1
Nothing has changed.


Something has. You just don't know what. I probably don't either. It may be a combination of factors that have added up. It could be the warmer weather you've likely had lately. Not letting the car cold idle certainly helps. If "several minutes" really means 10-12 minutes, then that could be a big part of the improvement.

You're right -- you don't get 50% better fuel economy by switching gas and fixing a leaky tire. You've got something else going on. Enjoy it!

 

[ARCOgraphite]

cross check a couple tanks with manual usage calculations.

Which car the Milan or the Accord? The accord should be getting 30MPG at least.
My Wife gets 32mpg ave on her Subaru ADW wagon 2.5L.

My rogue jumped from 21 - 25 mpg ave since the horrendously cold Winter last year!

 

[SwampSurvivor]

How long has it been since the average MPG was reset?

 

[OtisBlkR1]

The Honda (3.0) gets around 22-25 MPG average mixed driving around 29-33 highway depending on speed and terrain.

The Milan has never gotten anything better than 29 mpg doing 55 on flat terrain.. 20-22 average is the norm. Im blown away im seeing 30-32 MPG.

both of our sedans have the 6cyl in them. The Honda is the peppy one with like 260 factory HP (if memory serves) The Milan I believe is in the 220 HP neighborhood.

and no 1-3 minutes of warm up in the winter is about all I do.

 

[OtisBlkR1]

Originally Posted By: Miller88
How long has it been since the average MPG was reset?


at every fill up.

 

[mrsilv04]

Originally Posted By: OtisBlkR1
Originally Posted By: Miller88
How long has it been since the average MPG was reset?


at every fill up.


Let it run across 2 or 3 tanks, and see what it tells you.

 

[SirTanon]

Slightly out-of-bounds thinking here.. maybe your trip/mileage calculator is not precise? I only use mine as a 'rough' guide. For the real mileage calculation, I use an app on my phone and enter mileage and gas used at each fill up. The phone calculates it exactly.

Just my $.02

 

[JHZR2]

I noticed this with a rental minivan we had once. It was filled with six people and luggage, so pretty well laden. The one tire was leaky as partway on the use (we were using it in a general area and retracing our stops a lot), and we finally got a tpms code when it was looking pretty flat. After airing it up past placard pressure, we got above EPA rating.

I've found that adding lots of extra air to already properly set tires will only have marginal improvements, but filling a low one that's quite low can really yield an improvement. Iirc in the above case, it was sn increase from 25-28+

 

[CapriRacer]

I have been taking the same route for many months - filling up every other trip (Two round trips = 3/4 tank!). From time to time I will get fantastic mileage - and other times, not so much. I suspect this has to do with the percentage of ethanol in the mix, but I just really don't know.

 

[Papa Bear]

I live next door to a Canadian Tire gas bar here. (Leamington, On CANADA)
I used to operate a gas station in the 1980's and I'm interested in cars/fuels etc.

I often stop and talk with the tanker drivers while they are fuelling the gas bar next door. The fuel is sourced from the easiest available location and seldom comes from the same depot or refinery for that matter.

The gas comes from Sunoco/Esso/Shell (whoever has what is needed at the time regular/premium/diesel) and the fuel can come from Sarnia, London, Nanticoke depots.

There is seldom (never) the same fuel in the ground from one week to the next.

 

[ARCOgraphite]

Take a sample of gas and add a measure qty of dyed water too it to gauge ethanol percent. The H20 will force a phase separation. measure the remaing petrol vs the original before water addition.

 

[SirTanon]

Ethanol is definitely a possibility here, as it contains about 60% the energy/liter compared to gasoline. If the gas is 10% ethanol, then you're losing about 4% energy/mileage. This is even more pronounced if the gas has a higher percentage of ethanol. Also, if the ethanol has absorbed any appreciable water, then you're losing more energy/gallon.

 

[deanm11]

Which motor/trans is this Milan? Then we can establish how reasonable your current reported mileage is now, regardless of what it was in the past. I've ballparked winter blend gas vs. regular gas in my cars and they vary... the worst ones though lose only 4-5% on winter blend.

Has your recent driving possibly been more conducive to mileage? Frequently the best mileage is on flat country two-lanes... eg. 50mph, way before serious aerodynamic drag and little to no lights/stop signs. Optimal mileage is all about maintaining momentum.

 

[OtisBlkR1]

Well, I need to change this post from im perplexed to im a idiot.. so last night im chewing on this post as im detailing out my car with my little boy. As im vacuuming I look up and he is pushing buttons on the dash playing with the cars computer..

((((and the clouds part)))

I ask him what he's doing ? pushing buttons dad !!

So I investigate.. that 30-31mph is the AVERAGE MPG not the actual current MPG (the car is equipped with two) a real time and a average..

after I had filled up last week, somebody was pushing buttons on the dash after dad had reset everything..

Im getting a average (per tank of 30mpg) My mixed driving is still yielding about 20 mpg mixed..

Ok, its ok.. everyone can point and laugh now

 

[geeman789]

Calculate mileage the old fashioned way... fill tank. Set trip meter to 0. Drive.

Next time you get gas, record the number of miles driven. Now record how much gas you put in. Do the math.

Drove 200 miles, put in 10 gallons of gas... presto, 20 mpg...!

Onboard computers, at least in my experience, seem to be highly variable in their calculations... usually on the optimistic side.