Terrible gas mileage!

[Kenv24]

The new tires could be 3,4 pounds heavier.
That would do it.
Every pound of rotational mass effect equals two pounds of static mass.
Electric motors would be affected by this.

True. Didn’t think about the weight.

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[Larrythelunatic]

No mention is made of inflation numbers.
BIG influence on mileage!

 

[Cherokee]

True. Didn’t think about the weight.

Manufacturers choose the lightest ties when they can so they can show better mpg’s.

 

[MakinDoForNow]

True. Didn’t think about the weight.

I just checked the defender 2 is 27.8 lbs. If I remember correctly the oem conti's were 24 lbs.

 

[Wahjahbvious]

Worth it. The Defender is a hell of a tire. My top pick for highway driving, on any model it fits.

I just checked the defender 2 is 27.8 lbs. If I remember correctly the oem conti's were 24 lbs.

 

[MaverickDragon]

The new tires could be 3,4 pounds heavier.
That would do it.
Every pound of rotational mass effect equals two pounds of static mass.
Electric motors would be affected by this.

Agreed the weight will affect MPGs.
The typical rule I've seen is 1 pound unsprung = 10 pounds sprung weight of impact.
100 pounds of additional weight is said to be apprx equal to about a 1% MPG reduction.

4 pounds heavier per wheel x 4 wheels x 10 impact factor = 160 pound effect or 1.6% MPG decrease.
For the example noted by @710-oil-614 the 8 pound addition would equate to 320 pound load net.
That would be a 3.3% mpg reduction, and he noted a decrease substantially larger than that.
Of course, there are a lot of other factors that influence MPGs, especially temperatures where a hybrid suffers in battery and decrease and Atkinson increase to support heating the cab etc...

 

[710-oil-614]

Agreed the weight will affect MPGs.
The typical rule I've seen is 1 pound unsprung = 10 pounds sprung weight of impact.
100 pounds of additional weight is said to be apprx equal to about a 1% MPG reduction.

4 pounds heavier per wheel x 4 wheels x 10 impact factor = 160 pound effect or 1.6% MPG decrease.
For the example noted by @710-oil-614 the 8 pound addition would equate to 320 pound load net.
That would be a 3.3% mpg reduction, and he noted a decrease substantially larger than that.
Of course, there are a lot of other factors that influence MPGs, especially temperatures where a hybrid suffers in battery and decrease and Atkinson increase to support heating the cab etc...

For my specific case you would need to calculate the increase in rolling resistance from the tread and the increased size.

Wider tire size is 4.5% (225 v. 235) plus the additional rolling resistance from the Goodyear HT to the Wildpeak AT Trail. The US doesn’t classify rolling resistance of tires but the EU does and the territory HT are rated class A (most efficient) and the Wildpeak AT Trails are rated class D (second least efficient) which can account for as much as a 10% difference in efficiency.

So add up the 3.3% (weight), 4.5% (surface area), and 10% (rolling resistance) and you can start to see how it is a significant impact to the efficiency.

However tires only consume around 20% of a vehicles energy so that really ends up being around 5% efficiency loss due to the tires.

However - the two power choices (ICE v Electric) are not equally efficient and the heavier, wider, and harder to roll tires force the far less efficient ICE engine to run at a greater percentage than previous which is where the true efficiency is lost. Anytime the gas engine is running in the hybrid (obviously) it’s a big hit to efficiency.

In the end - going from Territory HT to 235 Wildpeak AT has cost me at least 10% in efficiency. The numbers above support than as do my hand calculated MPGs since putting them on.

 

[MaverickDragon]

In the end - going from Territory HT to 235 Wildpeak AT has cost me at least 10% in efficiency. The numbers above support than as do my hand calculated MPGs since putting them on.

Wow - That's a significant hit.
I was planning on going to the WildPeaks as I really like them on another vehicle.
Has your mpg calculations mostly been in cold weather as well?

 

[710-oil-614]

Wow - That's a significant hit.
I was planning on going to the WildPeaks as I really like them on another vehicle.
Has your mpg calculations mostly been in cold weather as well?

It has and I’m down around 20% total from summer months so the 10% I am attributing to it is not due to the cold.

I would recommend sticking to the 225/55/19s which are SL rated if looking at the Wildpeak trails. Those are less than 4lbs heavier per tire over the Territory HT.

If you don’t have a Lariat I would like at the Firestone defender at 2 which are incredibly light for an AT tire.

I’m very happy with the Wildpeaks. The hit to efficiency is something I have to live with and I’m okay with it.

 

[Kenv24]

I just checked the defender 2 is 27.8 lbs. If I remember correctly the oem conti's were 24 lbs.

Yeah, I’m surprised that it’s that much difference. I’ll have to look at the weight over stock when looking for new tires also.

 

[MaverickDragon]

@710-oil-614
With my XL, I'm running on the stock steelies and Conti Procontact XT 225 65 17's.
With a wheel and tire upgrade, the same size rims with WildPeaks would add 6 pounds more per corner (5 for the tire and 1 for the wheel). for a ~ 240 pound effect or maybe a 2.4% impact (or not).

The rolling resistance factor of the Conti's is a 'B" and the Falkens,a "D" (as you noted) but how to assess that difference into a mileage impact factor appears to be a unicorn, although there likely is an impact, as the stock rubber is designed to be a fuel efficient tire and the WildPeaks are more focused for where the pavement ends.

BTW - The Defender 2's in my size are only 1 pound lighter than the WildPeak Trails.

Considering how much dirt / rock road travel I do, which is always, although I like the mileage with the Conti's I don't know how well they will stand up to constant abuse.

The WildPeaks don't seem to mind the local roads at all.

 

[RadioDoc]

So what I've found with my '23 is that repeated short trips (<5 miles) will kill the gas mileage. I thought I was going to see my MPG jump living just 3 miles from work with max speed of 30 mph, but the reality is the ICE needs to kick on a lot more often to boost the hybrid battery (averaging about 36-38, down from 41-42 when my commute was around 15 miles each way). Speeds over 45 mph kill the gas mileage - not enough power to regularly maintain 45+ in electric only. Cold temps hurt gas mileage since the ICE needs to run more to warm up. Just driving in "Normal" hurts because the braking profile in normal jumps almost instantly to max regen + brakes whereas "Slippery" and "Eco" modes give me a lot more control over regen application.

There's a lot of factors that go into how this truck handles the MPG. While it's only upper 30's for me right now, I'm still averaging double what I'd get in a full size pickup so whatever, I'm happy with it.

 

[MakinDoForNow]

Yeah, I’m surprised that it’s that much difference. I’ll have to look at the weight over stock when looking for new tires also.

Look at the Continental true contact tour 54 good for weight, rolling resistance, wet and light snow, 70-80k milage, even have 225&235/55 R19 for $219 at discount.

 

[Edge Haley]

So what I've found with my '23 is that repeated short trips (<5 miles) will kill the gas mileage. I thought I was going to see my MPG jump living just 3 miles from work with max speed of 30 mph, but the reality is the ICE needs to kick on a lot more often to boost the hybrid battery (averaging about 36-38, down from 41-42 when my commute was around 15 miles each way). Speeds over 45 mph kill the gas mileage - not enough power to regularly maintain 45+ in electric only. Cold temps hurt gas mileage since the ICE needs to run more to warm up. Just driving in "Normal" hurts because the braking profile in normal jumps almost instantly to max regen + brakes whereas "Slippery" and "Eco" modes give me a lot more control over regen application.

There's a lot of factors that go into how this truck handles the MPG. While it's only upper 30's for me right now, I'm still averaging double what I'd get in a full size pickup so whatever, I'm happy with it.

Might try this…I ride until near empty then add 2 gallons higher octane, and fill up with lower grade…That extra octane gives me pretty consistent 42-43 mpg. But recent Michilens Defender tires dropped my MPG by 2 to 3 mpg…Pretty sure it was the tall tread and tread pattern creating wind resistance. Tire weight was close to the same.

 

[710-oil-614]

Might try this…I ride until near empty then add 2 gallons higher octane, and fill up with lower grade…That extra octane gives me pretty consistent 42-43 mpg. But recent Michilens Defender tires dropped my MPG by 2 to 3 mpg…Pretty sure it was the tall tread and tread pattern creating wind resistance. Tire weight was close to the same.

Tread and height would create more rolling resistance than wind resistance.

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