Michigan State Police Put Pursuit Vehicles to the Test to Find America's Next Top Police Car

[GTPNewsWire]

This is the discussion thread for a recent post on GTPlanet:

Michigan State Police Put Pursuit Vehicles to the Test to Find America's Next Top Police Car

This article was published by Joe Donaldson (@Joey D) on December 10th, 2018 in the Automotive News category.

 

[Obelisk]

I'm surprised that the Explorer SUV topped a ton of the entries in performance. That's impressive engineering by Ford.

 

[Exorcet]

I'm surprised that the Explorer SUV topped a ton of the entries in performance. That's impressive engineering by Ford.

I wonder how much the addition of police equipment played a role. If a lot of weight is added to the interceptors, then the SUV's might take less of a performance hit, though it's not like the Charger is a light car to begin with.

 

[ss3]

Before reading this I already knew the explorer was going to be the fastest, I’m not surprised it still is. Mostly because I’ve read somewhere and from past tests that it was the fastest

 

[flatdarkmars]

The RWD Chargers were the top of the tree in this [braking] test, slowing down in 126.9 feet with the V6 and 128 feet for the V8. Weirdly, the AWD V8 Charger took 133.8 feet to come to a stop.

What's weird about this? You should expect the AWD car, with its heavier drive train, to have a longer braking distance.

 

[Exorcet]

What's weird about this? You should expect the AWD car, with its heavier drive train, to have a longer braking distance.

Well that weight will also increase the friction of the tires and should more or less cancel out the weight penalty unless you're doing braking cycles where the added weight will contribute to brake fade. Distributing weight to all the tires is probably more influential, and with the Charger being front heavy I'd guess the AWD RWD would have the more even weight distribution.

EDIT

Tripped over myself there, somehow I was considering the Charger as if it was front wheel drive.

 

[Joey D]

What's weird about this? You should expect the AWD car, with its heavier drive train, to have a longer braking distance.

The weight difference is less than 200lbs. The RWD Charger is 4,325 lbs whereas the AWD is 4,520 lbs. I don't believe that's not enough to account for a difference of nearly six feet assuming all things are equal on the two cars aside for the drive wheels. It's even stranger that the 4,849 lbs Durango stopped shorter than it too.

 

[flatdarkmars]

Well that weight will also increase the friction of the tires and should more or less cancel out the weight penalty ...

You are correct, but these factors only cancel out if friction force scales linearly with respect to vertical load, which turns out to not be true of car tires. As load increases, grip increases, but at a declining rate (scroll down to Section 3 at this link). More discussion here.

So in actual practice, increased weight does increase stopping distance somewhat. As tire rubber is compressed under load, it effectively becomes harder and smoother, reducing its coefficient of friction.

The weight difference is less than 200lbs. The RWD Charger is 4,325 lbs whereas the AWD is 4,520 lbs. I don't believe that's not enough to account for a difference of nearly six feet assuming all things are equal on the two cars aside for the drive wheels. It's even stranger that the 4,849 lbs Durango stopped shorter than it too.

So when you do the math, 4520 lbs is 104.5% of 4325 lbs, and also 133.8 feet is 104.5% of 128 feet. Even I'm surprised at how neatly the numbers worked out.

The Durango is a completely different matter because it's almost certainly not on the same tires, and weight transfer will work a little differently because it's center of mass isn't in the same place, etc.

 

[Beeblebrox237]

The Explorer may have been the performance king, but I've heard that because the cars spend most of their time idling that the turbochargers end up not being properly lubricated for most of the time the engine is running, which in turn means the bearings and seals go bad and the turbos fail very rapidly.

 

[flatdarkmars]

The Explorer may have been the performance king, but I've heard that because the cars spend most of their time idling that the turbochargers end up not being properly lubricated for most of the time the engine is running, which in turn means the bearings and seals go bad and the turbos fail very rapidly.

Interesting! That seems like something that could be compensated for in the design of the lubrication systems, now that they know to expect it. Hopefully this knowledge will be applied to the next generation of turbocharged police cars, if not as a retrofit to this generation.

 

[Exorcet]

So when you do the math, 4520 lbs is 104.5% of 4325 lbs, and also 133.8 feet is 104.5% of 128 feet. Even I'm surprised at how neatly the numbers worked out.

Good observation, the numbers are spot on here. From that I'd suppose if they're on the same tires, the rubber might be slightly favor for the RWD. Although if that is the case, it didn't help the RWD configuration on the track.

 

[Beeblebrox237]

Interesting! That seems like something that could be compensated for in the design of the lubrication systems, now that they know to expect it. Hopefully this knowledge will be applied to the next generation of turbocharged police cars, if not as a retrofit to this generation.

I don't know if it could be retrofitted easily but it definitely needs to be taken into account in the future. For now I've heard a lot of police departments are replacing their old ecoboost models with the much slower NA versions.

 

[austindeckerGT5]

Well **** if it weren't for radios my GTI could outrun them lol. My slightly modded VR6 I was able to hit 140mph but my big turbo 1.8t thats gutted and pretty much track ready would be able to walk away from them. Until the radios catch me lol. Still not gonna try it because I know better then to put others lives in danger, including mine on the public roads. Keep the shenanigans on the track.

 

[abm89]

Would not be surprised if they have a de-tuned Ford GT V6 in that Explorer (aka the raptor engine)

 

[Eunos_Cosmo]

Everytime I see one of these Explorers it's at WOT with the turbos screaming their heads off. I'm pretty sure the Police enjoy them.

 

[coryclifford]

… having worked for a Lieutenant of the Columbus Fire Dept. for 15 years, I know, not police but it's the same, but it comes down to the city budget allotment and the best bid. Thats the important word. Bid. Contract costs.

That's why Columbus at least, has changed manufacturers occasionally. He'd say, this new one sucks, last year car or SUV was better. Next year, same story, different brand. Always an American brand. Big three.

I see different manufactured cop cars every few years, too. Known on paper to be worse than other manufacturers.

City budgets over performance.

 

[DaveTheStalker]

A friend of mine builds Explorers at the Chicago plant. The Interceptors are stripped down to the point of the average person would not want to own one. He owns a 2016 Explorer Sport twin turbo V6. It actually is pretty quick for a beast of a truck. Based on things I’ve been told that go on in that plant, I wouldn’t buy one. Quality is no longer “job 1”. With the UAW, it’s really hard to lose your job.

 

[Keef]

Odd that we're just now seeing this article. This story is from way back in early October.

Also interesting is that the cops tested the new Ford Explorer. Nobody at the time seemed to mention that this cop car was the new Explorer in diguise, showing of its new proportions and rear-drive Aviator chassis, and production headlights, etc. It wasn't until a month or more later that Autoblog posted spy photos of the civilian Explorer.

 

[Joey D]

Odd that we're just now seeing this article. This story is from way back in early October.

Also interesting is that the cops tested the new Ford Explorer. Nobody at the time seemed to mention that this cop car was the new Explorer in diguise, showing of its new proportions and rear-drive Aviator chassis, and production headlights, etc. It wasn't until a month or more later that Autoblog posted spy photos of the civilian Explorer.

Those were just prelim results. MSP only released the full report recently.

 

[Tornado]

Everytime I see one of these Explorers it's at WOT with the turbos screaming their heads off. I'm pretty sure the Police enjoy them.

Probably happy that they aren't the guy who got stuck with a Taurus.





Of course at the end of the day:

… having worked for a Lieutenant of the Columbus Fire Dept. for 15 years, I know, not police but it's the same, but it comes down to the city budget allotment and the best bid. Thats the important word. Bid. Contract costs.

That's why Columbus at least, has changed manufacturers occasionally. He'd say, this new one sucks, last year car or SUV was better. Next year, same story, different brand. Always an American brand. Big three.

I see different manufactured cop cars every few years, too. Known on paper to be worse than other manufacturers.

City budgets over performance.

This is the only thing that matters. It's how things like the Impala had such a long run as a police vehicle when everyone hated them and even the W-Bodies GM actually expected people to go into a dealership to pay for (instead of, say, a Camry) started falling apart immediately after the 36,000 miles ran up and had transmissions/suspensions made of balsa wood.

 

[Keef]

Those were just prelim results. MSP only released the full report recently.

It took the government two months to publish some VBox numbers?

I mean, I'm not sure what I expected.