Gas-mileage with SmartStopStart?

[cwadle]

So essentially, Ive driven my jeep around 400 Miles now, and I have averaged 13.4 Miles per gallon.
The vast majority (95%) of my driving is only city driving, but this seems a bit extreme. Now I understand the conditions I put my jeep in don't exactly promote good gas-mileage, but this seems a bit extreme.
Now here are the possible factors in my fuel efficiency.

• Model type is Rubicon
• SmartStopStart installed
• Winter time in Michigan
• 95% city driving
• Mild driving, not super aggressive
• Engine break in period
• Most trips average under 20 miles.
• Tires are 40 PSI

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[WXman]

That seems about right. My Sport bagged up a hand calculated 15.7 MPGs on the last tank with my ESS system not operational. And that's a roughly 50/50 mix of city and highway.

With the ESS system working, I'm three days into this tank and the dash is showing 18.9 or so. I'll hand calculate the true number at the end of the tank. Will probably settle in around 18 even.

ESS does make a difference. And, since you're purely city driving that hurts also.

 

[JC2692]

I get 18-19 mpg with at least 80% city driving and 37" tires. I shift often and early, coast to all stops, and use ESS.

 

[3illy]

So essentially, Ive driven my jeep around 400 Miles now, and I have averaged 13.4 Miles per gallon.
The vast majority (95%) of my driving is only city driving, but this seems a bit extreme. Now I understand the conditions I put my jeep in don't exactly promote good gas-mileage, but this seems a bit extreme.
Now here are the possible factors in my fuel efficiency.

• Model type is Rubicon
• SmartStopStart installed
• Winter time in Michigan
• 95% city driving
• Mild driving, not super aggressive
• Engine break in period
• Most trips average under 20 miles.
• Tires are 40 PSI

My fuel economy is terrible as well. 19 JLUS, 900 miles, bone stock. Average around 14.5MPG city. Going to take it in to dealer for center console repair and mention the mileage issue. I feel like the down shifting on the auto trans is a bit aggressive - as in when coasting to a red light I'll come to an idle crawl long before I reach the light. I am also not driving aggressively and try and keep it under 4k RPM if I can. Under acceleration I usually try and keep it in the power band betwixt 2.3 and 3.5k RPM. My daily commute is about 20 miles round trip.

 

[Jeeporama]

Well we've had a quite a stretch of very cold weather and snow, my city has insane amounts of traffic, and I achieved the poorest fuel economy so far since I've owned my JLUR (converts to about 13.8 MPG) However, 17 MPG was common when the weather was better, so considering how much stopping is involved when driving my beautiful non-aerodynamic tall brick, I think the ESS is making a difference in the city.

Regardless, I knew what I was getting into when I bought it, it's not a little fuel sipping boring vehicle, it's a thristy awesome sauce vehicle

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[Majestic]

So essentially, Ive driven my jeep around 400 Miles now, and I have averaged 13.4 Miles per gallon.
The vast majority (95%) of my driving is only city driving, but this seems a bit extreme. Now I understand the conditions I put my jeep in don't exactly promote good gas-mileage, but this seems a bit extreme.
Now here are the possible factors in my fuel efficiency.

• Model type is Rubicon
• SmartStopStart installed
• Winter time in Michigan
• 95% city driving
• Mild driving, not super aggressive
• Engine break in period
• Most trips average under 20 miles.
• Tires are 40 PSI

Would you be remote starting the Jeep to warm it up? That might impact your mileage.

 

[Zazoh]

18.7 mpg
3.6 with automatic

I no longer use ESS I tried two tanks with two tanks off, all 4 in 18 range. Now when I start Jeep, just automatically push to cancel Auto Stop.

No snow or REAL cold where I live.

 

[WranglerMan]

Here’s my specs:

2018 JLU Sahara 3.6 A/T
RC 2.5” boost
Method MR312 wheels
BFG 315x75R17 KO2’s
Tazer JL 11.06 ( just used to change a few vehicle settings )
Smart Stop/Start for ESS
ROAM slim front bumper with RC 9500 winch

When I first got my stock JL I was getting 22 hwy and 19 city and now with all the mods I have done i am getting 18.2-18.6 and this is calculated by the JL and on paper for each fill up, I tried running ESS the entire time and it honestly seemed to no affect the mpg’s that much

 

[Uhdinator]

JLR 2 dr 3.6 6 spd
JLR 2 dr 3.6 8 spd
JLR 2 dr 2.0 8 spd
JLUR 4 dr 3.6 6 spd
JLUR 4 dr 3.6 8 spd
JLUR 4 dr 2.0 8 spd

JL 2 dr 3.6 6 spd
JL 2 dr 3.6 8 spd
JL 2 dr 2.0 8 spd = 18.5-23 MPG, ESS on, 32x12 tires@ 32 psi, speedo recalibrated, 65 mph or less, 91-93 octane, cruise on @ 25-65 mph as much as possible.
JLU 4 dr 3.6 6 spd
JLU 4 dr 3.6 8 spd
JLU 4 dr 2.0 8 sod

7th and 8th gear auto over drive ratio: .84/.67
5th and 6th gear Man over drive ratio: .81/.72

Rubicon gearing highway RPM is above 2K
Non Rubicon gearing highway RPM below 2K (my 2.0 is around 1600 @ 65 mph)

Lots of variables like added weight from bigger/wider tires, bumpers, racks, winches, passengers, cargo. etc..etc..

 

[Rahneld]

So essentially, Ive driven my jeep around 400 Miles now, and I have averaged 13.4 Miles per gallon.
The vast majority (95%) of my driving is only city driving, but this seems a bit extreme. Now I understand the conditions I put my jeep in don't exactly promote good gas-mileage, but this seems a bit extreme.
Now here are the possible factors in my fuel efficiency.

• Model type is Rubicon
• SmartStopStart installed
• Winter time in Michigan
• 95% city driving
• Mild driving, not super aggressive
• Engine break in period
• Most trips average under 20 miles.
• Tires are 40 PSI

Would fuel octane be fair to add to that list?

As far as ESS saving you on gas is concerned, I tend to believe that if such savings even exist, they're probably not much for the average driver.

I especially think so when these possible savings are offset against costs of wear and tear, or such systems not working [as well] with vehicle age.

Maybe on the aggregate for all motorists with this feature, fuel savings and less CO2 have been found to add up--I just don't know.

 

[c20040215]

7is the magic number.

 

[AmericanMule]

So essentially, Ive driven my jeep around 400 Miles now, and I have averaged 13.4 Miles per gallon.
The vast majority (95%) of my driving is only city driving, but this seems a bit extreme. Now I understand the conditions I put my jeep in don't exactly promote good gas-mileage, but this seems a bit extreme.
Now here are the possible factors in my fuel efficiency.

• Model type is Rubicon
• SmartStopStart installed
• Winter time in Michigan
• 95% city driving
• Mild driving, not super aggressive
• Engine break in period
• Most trips average under 20 miles.
• Tires are 40 PSI

I'm running close to the same. I was running 17.3 mpg for the first 7000 miles. I since then have changed from the plastic front and rear bumper to steel bumpers. Plastic inner and outer fender, to steel and aluminum inner fender and beefier step rails.

I also am driving in snow conditions and city driving for the most part and no highway. Also most trips under 10 miles. I'm not aggressive.

SmartStopStart installed as well.

Tire pressure 40. New 315/70R17 on aftermarket +1 offset Fuel Zephyr.

Now I'm at 13.5. I will be running like this with some changes in the next week and see how it changes.

I'll let you know my findings with the changes.

 

[RMojitoJL]

I got my mopar 2" lift and 37 toyo MT's put on 2 wks ago... i do 50% city and 50% highway weekly... and i'm getting 17 by calculation (Not by dash) and yes the speedo is corrected. Of course I don't nail the gas every red light either (I just sold my 1000hp Hellcat) if I wanted a racecar I would of kept it

 

[Austin TX Jeep Rubicon]

So essentially, Ive driven my jeep around 400 Miles now, and I have averaged 13.4 Miles per gallon.
The vast majority (95%) of my driving is only city driving, but this seems a bit extreme. Now I understand the conditions I put my jeep in don't exactly promote good gas-mileage, but this seems a bit extreme.
Now here are the possible factors in my fuel efficiency.

• Model type is Rubicon
• SmartStopStart installed
• Winter time in Michigan
• 95% city driving
• Mild driving, not super aggressive
• Engine break in period
• Most trips average under 20 miles.
• Tires are 40 PSI

I've driven my jeep around 1500 Miles now, and I have averaged 16.9 Miles per gallon.
The vast majority (95%) of my driving is only city driving, but this seems a bit extreme.
Now here are the possible factors in my fuel efficiency.

• Model type is Rubicon
• SmartStopStart installed
• Winter time in Texas
• 95% city driving
• Mild driving, not super aggressive
• Most trips average under 20 miles.
• Tires are 36 PSI

 

[drdriller]

I don't even check or care what my MPG is. If I was really worried, I would have bought a Prius.

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