Milage not what I expected

[MPMB]

It's not about stress testing, it's about the added charging/load cycles on the batteries and starter that people don't like. Batteries and starters have a rated lifespan, for batteries it's around 250-500 cycles more for lead-acid. For starters it's usually the contactors that fail, or a winding in the motor from the shock through the shaft at an angle overtime. Using those components more often WILL lead to an earlier failure, how much earlier isn't a guarantee. But it does improve chances you'll spend money fixing it when they fail sooner, and in theory that means more potential profit for manufacturers.

Like I said, the systems are engineered for this use.

It's one of the reasons vehicles are using AGM batteries instead of lead acid, and why Jeep decided to run 2 batteries (they have a stellar electrical engineering department, don't they?). However, most mechanic blog people tend to believe that batteries (regardless of type) are degrading quicker with ESS. Lithium-based batteries are too expensive at scale for mfgs to swap to, but those may be a better alternative.

The starters are not the same starters that were bolted to the bell housing of a 350ci SBC that you could whack with a hammer to engage. These have been designed for the purpose of ESS systems. Instead of a 30,000-50,000 duty cycle, they're engineered to last 250,000 cycles.

Let's do the math.

Let's say a vehicle uses it's starter 4x a day on average. That's 1,460x a year. Standard starters are designed for 30,000 cycles, so that's 20 years of service in optimum conditions.

Let's say an ESS-equipped vehicle cycles on/off 20x a day on average. Hell, let's double that and make it 40x. That's 14,600x a year. For an ESS-starter designed for 250,000 cycles, that's 17 years of service.

Not a huge difference, and it likely more than evens out when you add in the starting/restarting conditions. Starting a cold engine is a lot harder than starting a warm engine. So the ESS system isn't working as hard as the standard starting system.

And again... Honda is the only manufacturer to have major issues with their ESS system in the decade-plus it's been around. I would have bet VW would have had a horrific scandal/issue with their track record, and a typical domestic brand like GM/GMC/Cadillac failure.

To be clear, I'm not a fan of ESS either, I find it annoying and another nanny feature forced from upon high that adds more complexity without a positive return. Modern cars is why I really want my next ride to be something older than myself. If I have to unplug more s**t than unbolt... F that s**t.

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[MPMB]

On system reliability, I haven’t had my Gladiator as long as a lot of you but I keep seeing the issue with Aux battery and main battery mortality. I saw this from almost the start of looking at Gladiators with the system. I’m assuming most people experiencing this problem are using the stop/start function. If the main “beating heart” (literally) of a system is causing issues how can I trust the rest of the system to function as intended? I live about 30 minutes from town or even a Walmart so not a huge deal for me but I’m in town every day because the schools are better there and I’m Mr. Mom. I don’t turn it on in town and I don’t intend to because in my mind it will cause issues that I really don’t want to deal with. As soon as it comes up on my “Evil Plan to Take Over the World” the aux battery will be going bye bye and I’ll be installing a few batteries that will fit my needs. Just my $.02.

I usually turn it off manually. My wife leaves it on when she drives. Our JT hasn't been a commuter. Road trips pretty much eliminate the need for ESS anyway.

That said, my aux battery lasted 3 years. I started to get messages like "ESS not available" and some other random things, and the voltage was always 14v+, meaning things were always charging. So while I was "in" there (went through fender liner), I replaced both at the same time.


BOT of mileage/MPGs... Hauling a trailer does suck down the mpgs, even if it's a little one. Speed will definitely have a huge impact on mpg when towing.

 

[Badunit]

You guys are slacking. 4 pages in and I have to be the first to post the cow/jeep aerodynamics pic?

Maybe this would help:

 

[ChrisNLA]

Yeah I think theres a lot of trim level conflicts when it comes to MPG claims on this site. A Sport with cheap, light 31" all seasons is going to get better than a rubicon with heavy 33 all terrains, but I think a lot of folks don't take that into consideration, at least not at first.

In my past 3 vehicles I've consistently seen 5+ mpg improvements while in the mountains vs at home in the flats. Even towing my camper around Colorado I will often see the same and sometimes better mpgs than when I'm not towing at home in MN. But you ask anyone that lives in the mountains and they claim poor economy (I blame it on their need to fly at mach speed down mountain roads, where as I let it coast).

Unsurprisingly, I always see incrementally better fuel mileage driving home from somewhere several hours away, then I see driving to there - because everywhere is uphill from Louisiana

 

[NC_Overland]

Unsurprisingly, I always see incrementally better fuel mileage driving home from somewhere several hours away, then I see driving to there - because everywhere is uphill from Louisiana

This sounds crazy, but I saw zero difference in fuel economy/range when driving a few times per month between Raleigh and Chattanooga and back between two different routes. One went through the mtns in E TN/W NC and the other went south and avoided the mtns. They were within 20 miles distance of each other. The only thing that I could figure as to why the mtn route got the same mpg was because some was backroads doing 55-65 vs 75-80 the whole way on the southern route. That and coasting downhill on the mtns. Either way I got 21-23 mpg depending on traffic and the time of year.

 

[Dilly’S Willy]

Like I said, the systems are engineered for this use.

It's one of the reasons vehicles are using AGM batteries instead of lead acid, and why Jeep decided to run 2 batteries (they have a stellar electrical engineering department, don't they?). However, most mechanic blog people tend to believe that batteries (regardless of type) are degrading quicker with ESS. Lithium-based batteries are too expensive at scale for mfgs to swap to, but those may be a better alternative.

The starters are not the same starters that were bolted to the bell housing of a 350ci SBC that you could whack with a hammer to engage. These have been designed for the purpose of ESS systems. Instead of a 30,000-50,000 duty cycle, they're engineered to last 250,000 cycles.

AGM still use the lead-acid chemistry, just in a sealed design.

Lithium requires different (higher) operating voltages than lead-acid chemistry batteries for charging.

Mechanics slap on parts and more often don't understand how complex systems work. Technicians diagnose, repair, and sometimes create new solutions because they want to understand how things work, not just slap the new part and get paid. People who work in this industry understand what I'm talking about here.

Manufacturers may use different materials for starters, but they function the same way. Motors are motors, and chemistry is chemistry regarding batteries. No the material in the starter doesn't (generally) care where you mount it, all it cares about are the electrons and physics that make it work. No, the internal structure/design of materials inside a case doesn't change the fact you still use acid and lead plates to store DC voltage.


Please stop spreading misinformation. Manufacturers already do this, we don't need to keep that vicious cycle going.

 

[JTGuy]

When I want better MPG , I just slow down a little. At 60 my JT is much quieter and just cruse along with little effort.

 

[JTdiRtyD]

Like I said, the systems are engineered for this use.

It's one of the reasons vehicles are using AGM batteries instead of lead acid, and why Jeep decided to run 2 batteries (they have a stellar electrical engineering department, don't they?). However, most mechanic blog people tend to believe that batteries (regardless of type) are degrading quicker with ESS. Lithium-based batteries are too expensive at scale for mfgs to swap to, but those may be a better alternative.

AGM still use the lead-acid chemistry, just in a sealed design.

Lithium requires different (higher) operating voltages than lead-acid chemistry batteries for charging.

Lithium aren't great options for vehicle batteries because of temperature limitations. Charging under 40deg f can damage them, and discharging under -4 deg f will damage them, which means you need to run a heating system (like EV does), but now you're adding complexity, weight, and a constant draw in cold environments.

 

[Dilly’S Willy]

When I want better MPG , I just slow down a little. At 60 my JT is much quieter and just cruse along with little effort.

Exactly. I used CC yesterday in town and was getting a consistent 25-28mpg around town in 3rd gear (manual transmission, willys, 32" MTs)

 

[Patrol65]

Looks like if MPG means a lot stay away from Rubicons and Mojave’s. Plus keep it stock and don’t tow or load anything in the back. Well where is all the fun in that? Wonder the percentage of owners who keep it stock vs the ones who don’t.

Just with a smart cap and a DIY drawer system in the bed dropped me 2 MPG. Hearing the engine gets better mileage after breaking in gives me hope!!! Well some

 

[Bandit’s Lair]

 

[MPMB]

Looks like if MPG means a lot stay away from Rubicons and Mojave’s. Plus keep it stock and don’t tow or load anything in the back. Well where is all the fun in that? Wonder the percentage of owners who keep it stock vs the ones who don’t.

Just with a smart cap and a DIY drawer system in the bed dropped me 2 MPG. Hearing the engine gets better mileage after breaking in gives me hope!!! Well some

It's not rocket surgery.

MPG numbers are based on the most optimum setup, which is the Sport with its smoothie tires and bumper-to-fender air shields, lighter weight, and lower ride height. The Gladiator Jeep sent for testing was not a Rubi or Moj because it had a 3.73 gear ratio.

I forget the rule of thumb, but it's something like for every 200# it costs 2-4% mpg.

Bigger, heavier, chunkier tires drop mpgs.
Taller, heavier vehicles drop mpgs.
Towing drops mpgs.

But we already knew this going in - just looking at a Gladiator or Wrangler know it's not the most aerodynamic thing on the market.

 

[Stan H]

Looks like if MPG means a lot stay away from Rubicons and Mojave’s. Plus keep it stock and don’t tow or load anything in the back. Well where is all the fun in that? Wonder the percentage of owners who keep it stock vs the ones who don’t.

Just with a smart cap and a DIY drawer system in the bed dropped me 2 MPG. Hearing the engine gets better mileage after breaking in gives me hope!!! Well some

Mine gets great mileage . It's because you need a FAD . Get a FAD get your mileage back.

 

[Patrol65]

Honestly I had to google what a FAD was. How much mileage did u get back?

 

[Supazuk]

stock 19-20
I was getting about 20-22 w/ a K&N before lift and tires
35's about 17-18
add a lunch box front locker 16-16.5
forgot to clean the clean said K&N for 4 months and i got down to 14.5 mpg

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