Drove to Las Vegas from Santa Monica yesterday....321 miles/11.7 gals=27.5 mpg (California gas)

Drove back today 282 miles/8.9 gals= 31.7 mpg (Nevada gas)

I've always heard CA gas gives worse mileage...here's a direct comparison, same weather, same driving style (80 indicated with cruise on much of the time)

'07 MCSa with 2000 miles on the clock....still pretty new :-)

 

If it means anything, a friend from the Mini dealer told me that the amount of ethanol in the gas you're buying may affect performance. That would include the mpg that you're getting from a particular gas station. I don't know if it's true but I had problems stalling when in very cold weather (Northeast) and was told that it may be as a result of ethanol.

 

It is down hill from Vegas to Santa Monica.
Las Vegas elevation: 2178 ft.
Santa Monica elevation: 101 ft.


I was wondering why I was not getting as good mileage as others posting on NAM. Hadn't heard that our California boutique gas gave worse mileage. At least the air is a lot clearer than it was when I was growing up in Brentwood, and the Pacific Palisades. There was some nasty air in those days, and now there are a lot more cars on the road.

I did realize lately that my driveway puts a serious dent in my average mpg. I set my trip computer when I recently got gas in Seaside (Shell 91). It was 14 miles home. When I reached the bottom of the drive, it was reading 28.6 mpg. At the top of the drive, the average had changed to 27.7.

I guess ya gotta pay for a view like this:

 

so thats where you get all that wood for your shift *****...

 

I'll second Robin's comment. I just came across I-40 eastbound (from Tehachapi to Phoenix) and there is about a 30 mile upgrade along the way. If that's the route you took, it would certainly effect your overall mileage.

 

That is 100% true. In New Mexico the gas stations switch to a mix of 15% ethanol in the winter, and I'm doing good to get 25 MPG this winter as a result. During the summer I average around 30, and I actually drive a little more aggressively in the summer.

Ethanol sucks IMO.

 

According to my computer I did 40.1 mpg avg. from Miami to Daytona last fall. 38.4 mpg on the way back. I went up a little in avg. speed on the way home.

 

You must have been driving really slow. I have never gotten any better than 28 driving the MCS at around 90 to 100mph.

Consumption being higher in one direction could be affected by travelling from a lower location to a higher one - like when going to ski...

And yes, some states mandate the mix of some bad stuff in your gas during the winter and it makes the engine less efficient, unless you have a chip and can program the ECM for lower quality fuel (have this on my 07 Suburban)...

 

I am averaging 30.4 in city using 91 Shell. '07 Pepper White MCS, Auto, Piano Black, Dual Panaramic Sunroof, not bad for beautiful COLORADO!

 

Can't say for my MINI, but on my 5-series we noticed a definite change in the ethanol/non-ethanol gas. We drove from Houston to Clearwater, FL, and return, on I-10, and the same local highways. Not a whole lot of variation there! When we were able to get non-ethanol gas we noticed about 2-3 mpg gain on the computer's instant readout, using the same speeds and cruise control. It went from about 25 to 26 to 28+. We only use 93 octane, and usually Shell.

This jibes with what we've seen in a variety of cars, when the same-everything could be approximated. Everything's pretty flat here.

 

Sometime in October I noticed a 3-4 mpg drop in milage. I am waiting for them to switch back to summer fuel.

 

Ethanol is not good for gas burning engines. We should use the corn for other things. On older cars and motorcycle with carbs don't use ethanol it will clog up the carbs.

 

We are fortunate that the county "above" us has non-ethanol fuel. We fill up our '64 Porsche SC there--pretty much all the time. And we worry about the next "cure" that's foisted upon us...

 

Stupid winter gas! I hates you!

I think we're supposed to have special 'cleaner burning' summer gas here next summer too. It's the price we had to pay to get rid of those accursed E-Checks. I hope it isn't equally bad.

 

What's an E-check? 'Round here it's a bank thing.

 

Does California oxygenate the fuel? I know here in Colorado during the winter months they oxygenate the fuel to fight the "brown cloud". It's widely known here that Winter gas gets less mpg than Summer fuel.

 

I just finished up a tank of gas averaging 36 mpg @ 49.6 mph! Most of it was my commute but, some was in town. I tried to see how much I could get by being careful, but not too careful . Generally I average about 33.5.

 

Let's all remember running other than stock rim and tire size will effect the mileage calculations.

I assume the speedo and odo are set to the size rim the vehicle came with right? Mine seems to be off by 2-3 mph. I have 17" rims, with the Sport Package.

 

Here's a story confirming that ethanol in gas reduces efficiency:
http://www.planetark.com/dailynewsst...5388/story.htm

Here is an article showing that these biofuels increase greehouse gas
http://www.ictsd.org/weekly/08-02-13/inbrief.htm

So why are we adding ethanol to gas???

 

The only good reason I've heard is to replace MTBE, which is carcinogenic. However, I suspect the real answer to your question would be large campaign donations from agro-business. As far as global warming and energy conservation, I've been hearing for a longtime that the production of ethanol consumes more energy (oil) that it contributes. Perhaps Haliburton has a stake in ethanol production.