Gas mileage accurate?

I was reading on Car and Driver online that the Shelby gets 14 and 21 mpg, respectively. Do we have any Shelby owners here to say if this is accurate?

On a 500 mile road trip mostly highway at about 75 mph I was getting 23mpg average. This was during engine break in so I varied rpm and engine load every so often. Not bad.

As for around town (lots of stop and go) I get about 11 mpg.

I got about 18 over 1300 highway miles, between 4th and 6th gear

Average right on 14. This is on work commutes on a 45 - 55mph stretch of road. Half of trip has stop lights, other half is wide open. That's not getting on the gas hard and not shifting above 4500.

Unless you drafted a tractor trailer for 500 miles I don't think 23mpg is going to be achievable very often. With over 2000 miles on the car the window sticker has been the Oracle at Delphi for me. About 21 hwy, 14 city. I'm at average of 16 for the 2000 miles with the healthy dose of spirited driving we all plan to do, but also cruising in 6th and a focus on economy when fun driving isn't practical. Remember, getting 18mpg instead of 15mpg is a 20% savings. The tires were over inflated on delivery so I corrected that pretty quick. On the track you'll see single digits (or good mountain road), and perhaps with hypermiling techniques you will beat 21 by a couple mpg. I predict the vast majority of us will stay within the predicted EPA envelope the vast majority of the time (on public roads). Tech/base owners might see another 0.5 mpg hwy due to lower drag, with identical driving technique. A lot working against econ here, high rolling resistance, short gearing, high drag (spoilers and cooling drag from radiators)

The 23 figure (rounded up from 22.5+) as determined by the trip computer readout and in the northeast metropolitan area which is not mountainous. Again, these were break in miles and did not try and hyper mile nor did I drive aggressively. I hope this figure is repeatable for my area on long trips.

TDC said:

The 23 figure (rounded up from 22.5+) as determined by the trip computer readout and in the northeast metropolitan area which is not mountainous. Again, these were break in miles and did not try and hyper mile nor did I drive aggressively. I hope this figure is repeatable for my area on long trips.

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I wasn't calling you a liar buddy so I hope you didn't take it that way! :cheers: is your car a tech pack? I also wonder if higher viscosity of the colder trans and diff oil in the track/R negatively effects efficiency in the winter especially. One day maybe I'll have the discipline to "be good" for a whole tank!

Didn't take it that way. Took it more as a discussion point that created an opportunity to look deeper into the reasoning why the mileage was decent. It's good to question the details and there's always room for bustin a little b's from time to time.:headbonk:

Yeah. The car is a tech pack. Would be interesting if the track pack spoiler makes a measurable difference.

I wonder how much the extra drag of the R will affect that?

DrumReaper said:

I wonder how much the extra drag of the R will affect that?

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My guess is they did the R for the EPA sticker baseline, so the normal ones should do a little better.

I get right at 14 around town and 23 or so for a steady 75 on the freeway.

I average 14.6 long term. I tried a snapshot today at a steady 65-70 for 60 miles, was 21.9 temp high 50's. I have about 1700 miles on it.

I have an average of 19 over 1300 miles. I am hoping that number gets smaller.

If you're worried about gas mileage, or range, or practicality... Don't do it.

Are you guys posting trip computer MPG figures, or are you hand calculating based on # of gallons and miles covered when you fill up? Most car MPG readouts are optimistic - sometimes by a great deal.

licktensteins said:

Are you guys posting trip computer MPG figures, or are you hand calculating based on # of gallons and miles covered when you fill up? Most car MPG readouts are optimistic - sometimes by a great deal.

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I've done hand calculations to check my last couple Mustangs and the MPG readout on the dash was pretty much right on.

I just got back from a longer highway drive and I was getting roughly 21.2 mpg at 79 mph and 23.7 at 75 mph - each over more than a hundred miles of highway.

I did have my snow tires on the car, though. They are 245 section width, so the rolling resistance is probably lower when compared to the factory rims/tires. I adjusted the mpg and speeds down from the dash readout because the diameter is also slightly smaller than the factory tires (27.03 versus 27.4 inches assuming the speedometer reads the rear tires. If it reads the fronts the mpg and speeds would be a little higher.).