Body on Frame vs Unibody

[peterk9]

.....Now if they could just design some dang road clearance into them and give them real 4wd instead of advertising awd as 4wd they could build a great truck.

I think Ford is already coming around to the AWD definition. I noticed that some literature in the 2011 Owner's Guide which was referred to as 4WD is now AWD in the 2014 Guide.

Also the demand for the good old ladder frame SUV is not there. That is the reason the 5th gen Explorer was born. Even Toyota is discontinuing the FJ Cruiser after this year.

Peter

 

[dtr]

BTW, Lee Iacoca solved the corrosion issues

Before his rust thru protection guarantee it was common to require 50 to 175 hrs of salt fog testing before putting stuff on cars.

Last I checked people were requiring testing for 600 to 1200 hrs before okaying stuff to go on cars.

there are plenty of unibody cars and minivans that work just fine from a corrosion perspective

 

[Explorer0204]

first, I am not trying to pick on you there just was a lot to comment about

I understand your point of view I just do not necessarily agree

corrosion can be handled relatively easily with more/thicker galvanizing

for over all safety in a collision (the way the lions share of collisions happen) unibody construction is the absolute clear winner. you are fooling yourself or are unfamiliar with how deformation of the car saves lives

I really do not know or care about towing as it is just not that important as flat bead trucks are popping up everywhere.

Why add weight to low stress areas in vehicles? go to any engineering college and I think they are all being educated to understand that we have better designs techniques available today. Trucks just do not need thick metal parts in low stress areas and that is one advantage of unibody.

Now if they could just design some dang road clearance into them and give them real 4wd instead of advertising awd as 4wd they could build a great truck.

By towing I mean towing with the vehicle, not towing the vehicle...

That is one case where frames are better and safer is for towing.

As for adding strength to low stress areas i see your point and for the record I am taking Mechanical Engineering as we speak so I understand some of the different design reasons that are made in the name of money and strength.

I'm just old school when it comes to suvs. I am of the mindset that they simply need to make what they are making now for people who want it and they should still make suvs for people who still use them to tow and haul stuff as they were originally made for. But... Like you said. People just wouldn't buy a mid size frame on body suv anymore so it is what it is. If you want a proper truck based suv you have to go full size which isn't a big deal.. Just sucks for people like me that pull up to 7k pounds and do mostly lighter towing and offloading that a third and 4th Gen explorer excells perfectly at I guess it is a bit depressing to me that my next vehicle will have to be a pickup of full size suv to do the things I want it to. It feels like a step backward to me... But for most people it isn't and I get that.

One last thing, I'm not sure how my post made so many waves here heheh but I do appreciate everyone rolling with it in good clean debate. Sometimes (apparently) controversial comments can become word wars which suck..

I know you uni body guys feel most of my claims are all wrong and to a degree some probably are.. But I guess I am just trying to bring to light the other side. Some of the disadvantages. EVERYTHING in the world had both advantages and disadvantages and I guess I was just trying to defend the other side.

 

[Explorer0204]

I think Ford is already coming around to the AWD definition. I noticed that some literature in the 2011 Owner's Guide which was referred to as 4WD is now AWD in the 2014 Guide.

Also the demand for the good old ladder frame SUV is not there. That is the reason the 5th gen Explorer was born. Even Toyota is discontinuing the FJ Cruiser after this year.

Peter

Correct me if I am wrong here....

The 5th gens (11 up) have 4x4 auto, 4x4 high and 4x4 Low????

Or is there no low range and therefore not a to say "true" 4x4 system.

What you don't like about the 4x4 system compared to say a 3rd or 4th gen??

 

[182RG]

Correct me if I am wrong here.... The 5th gens (11 up) have 4x4 auto, 4x4 high and 4x4 Low????

No. The system, 11 and up, is very similar to a Haldex (think Quattro) AWD system. Under normal conditions, it is FWD biased. The computer transfers variable power via a Power Transfer Unit to the rear wheels as needed. There is no Low/High. The computer has a Normal, Snow, Sand, and Off Road mode. This serves to turn Traction Control on/off via the anti lock braking mechanism, and adjusts the shift points based on the mode. There is nothing about this system that is 4WD. It is actually pretty refined. I would never go back to traditional 4WD. Makes it seem archaic by comparison.

 

[peterk9]

Correct me if I am wrong here....

The 5th gens (11 up) have 4x4 auto, 4x4 high and 4x4 Low????

Or is there no low range and therefore not a to say "true" 4x4 system.

What you don't like about the 4x4 system compared to say a 3rd or 4th gen??

There is no Hi or Lo 4X4 in the 5th gen. The AWD system is always active and requires no input from the driver. They have what is called a Terrain Management System (TMS). It is FWD biased but capable of sending power to the rear wheels when required. It has Normal, Mud & Ruts, Sand and Snow modes. Each has its own affect on the shift points, acceleration etc.

From the Owner's Guide;

The intelligent 4WD system continuously monitors vehicle conditions and
automatically adjusts the power distribution between the front and rear
wheels. It combines transparent all-surface operation with highly capable
four-wheel drive.
The 4WD system is always active and requires no driver input. It is
capable of handling all road conditions, including street and highway
driving as well as off-road and winter driving. The driver can optimize
more 4WD control by moving the terrain management switch for the
correct terrain

If you wish more info, you can download the PDF file of the Guide. It can be found at; https://owner.ford.com/servlet/Cont...oLogin=Owner/Page/OwnerGuidePage&ord=85100321

Just fill in Year, Make and Model and click on Find My Vehicle. Page 226 explains TMS.

I've never had any other Explorer. I found the ride to hard in the 2002 I test drove and went to the Toyota Highlanders for the next 10 years.

Peter

 

[Explorer0204]

There is no Hi or Lo 4X4 in the 5th gen. The AWD system is always active and requires no input from the driver. They have what is called a Terrain Management System (TMS). It is FWD biased but capable of sending power to the rear wheels when required. It has Normal, Mud & Ruts, Sand and Snow modes. Each has its own affect on the shift points, acceleration etc.

From the Owner's Guide;

The intelligent 4WD system continuously monitors vehicle conditions and
automatically adjusts the power distribution between the front and rear
wheels. It combines transparent all-surface operation with highly capable
four-wheel drive.
The 4WD system is always active and requires no driver input. It is
capable of handling all road conditions, including street and highway
driving as well as off-road and winter driving. The driver can optimize
more 4WD control by moving the terrain management switch for the
correct terrain

If you wish more info, you can download the PDF file of the Guide. It can be found at; https://owner.ford.com/servlet/ContentServer?pagename=Owner/Page/OwnerGuidePageVehicleLookup&BackToLogin=Owner/Page/OwnerGuidePage&ord=85100321

Just fill in Year, Make and Model and click on Find My Vehicle. Page 226 explains TMS.

I've never had any other Explorer. I found the ride to hard in the 2002 I test drove and went to the Toyota Highlanders for the next 10 years.

Peter

Ohh Dayyum that sucks!!! I thought they were still rwd based and had a proper transfer case.

Wow.. That is really disappointing to hear.

 

[colintrax]

Ohh Dayyum that sucks!!! I thought they were still rwd based and had a proper transfer case.

Wow.. That is really disappointing to hear.

Where have you been for the past 4 years? Lo

 

[OffTrac]

There is nothing about this system that is 4WD. It is actually pretty refined. I would never go back to traditional 4WD. Makes it seem archaic by comparison.

The new Explorer couldn't get from one side of our properties to the other with fancy traction control. Some people do still need true 4x4. Traction control AWD isn't necessarily more refined, it's just a nice safety feature. It does not serve the same function in any stretch of the imagination. It's only archaic if you can't imagine that people do access areas of this country without pavement or hard packed public beaches, which is what I assume the Sand mode is for.

 

[dtr]

No. The system, 11 and up, is very similar to a Haldex (think Quattro) AWD system. Under normal conditions, it is FWD biased. The computer transfers variable power via a Power Transfer Unit to the rear wheels as needed.

There is no Low/High. The computer has a Normal, Snow, Sand, and Off Road mode. This serves to turn Traction Control on/off via the anti lock breaking mechanism, and adjusts the shift points based on the mode.

There is nothing about this system that is 4WD. It is actually pretty refined. I would never go back to traditional 4WD. Makes it seem archaic by comparison.

It is a good AWD and reasonably competent from my reading. But real 4wd is more capable. There is nothing stopping Ford from having real 4wd as an option for some and AWD for most imo.

 

[182RG]

Traction control AWD isn't necessarily more refined

It is for a car based CUV which the Explorer is. Nobody is going to be rock crawling, or fording streams in these vehicles. They are asphalt assault vehicles, taking on 4 lane highways and Walmart parking lots. In this use, FWD biased AWD is much better suited. Better MPG, tire wear, easier to use.

Lockers, 4 Low, air suspension...not on a CUV. Not needed. Not wanted. I would not have bought one for the wife if it were truck based...

 

[dtr]

Sorry I misunderstood "towing" in a previous post.

The dodge durango is now unibody construction and can tow 7400 lbs. There is nothing wrong with unibody construction.

Ford either limited it due to brakes, transmission, or the desire to get people to buy a more expensive vehicle.

Other companies have real 4wd on unibody models.

I am not trying to debate new vs old EX as much as unibody vs frame.

Unibody has a lot of advantages, but that does not mean an auto company can not poorly design a unibody truck just like they have poorly designed frame trucks in the past. One poor design choice by an auto company should not bias you against the construction technique.

 

[OffTrac]

I don't really take issue with unibody design and do believe they are the future of vehicles as stronger, lighter metals become cheaper.

4x4 isn't only necessary for hard core situations. I'm in south Georgia where it's flat and sandy, not really hard core. I exercise 4wd frequently and when we had the Tahoe, only found Auto 4wd desirable on wet pavement. 4Hi was much more useful when actually off pavement.

 

[182RG]

The dodge durango is now unibody construction and can tow 7400 lbs. There is nothing wrong with unibody construction.

The limitation of 5000 lbs in the Explorer is due to the FWD / transverse engine setup. It has nothing to do with HP, Torque, or frame construction.

The Durango is RWD.

I don't see that changing in the Explorer.

 

[dtr]

The limitation of 5000 lbs in the Explorer is due to the FWD / transverse engine setup. It has nothing to do with HP, Torque, or frame construction.

The Durango is RWD.

I don't see that changing in the Explorer.

I do not think you are correct. The durango is rwd, but when it has a 6 cylinder in it the towing is close to 5000 lbs. Only with the v8 does it get up to 7000 lbs

the EX has a 6 cylinder so 5000 lb towing is similar to rwd with a 6

turbo makes a 6 more powerful, but it does not provide the low end torque of a v8 from a standing start

a unibody v8 expedition with fwd should provide a lot more towing capacity

 

[peterk9]

Towing Comparison

Dodge Durango 3.6L V6; RWD & AWD 6200 lbs.
5.7L V8 Hemi; RWD 7400 lbs., AWD 7200 lbs.
Ford Explorer 3.5L V6; FWD & AWD 5000 lbs.
3.5L V6 Ecoboost; AWD 5000 lbs.
2.0L I4; FWD 2000 lbs.

Peter

 

[dtr]

Dodge Durango 3.6L V6; RWD & AWD 6200 lbs.
5.7L V8 Hemi; RWD 7400 lbs., AWD 7200 lbs.
Ford Explorer 3.5L V6; FWD & AWD 5000 lbs.
3.5L V6 Ecoboost; AWD 5000 lbs.
2.0L I4; FWD 2000 lbs.

Peter

I think I misread the 6200 as 5200 so I guess I need to clean my screen

I concede the rwd does seem to help, but hard to say how much as the engines are slightly different and the car companies usually over claim capability.

Problem is I do not know if dodge has fudged things more or if Ford has fudged things more

 

[peterk9]

I think I misread the 6200 as 5200 so I guess I need to clean my screen

I concede the rwd does seem to help, but hard to say how much as the engines are slightly different and the car companies usually over claim capability.

Problem is I do not know if dodge has fudged things more or if Ford has fudged things more

It really doesn't matter to me since I don't have the tow package of tow anything. It is something I may consider getting if I get the 2015 Explorer, even though I don't have a use for it.

Peter

 

[182RG]

I do not think you are correct.

FWD bias also means a few other limitations for towing.

1st - Torque steer tendency is increased in a towing situation. The bigger the load, the harder the acceleration, the more the tendency exists.

2nd - Weight distribution shifts the balance towards the tongue of the trailer. As a shift to the rear occurs, the front becomes lighter and traction becomes an issue. Think wet roads, boat ramps, etc. Tire spin and safety become a concern.

As far as the 2015 Expedition, I expect it will continue to be RWD. None of the articles I've read indicate otherwise. The Explorer shares a platform with the Taurus. The Expedition shares a platform with the F-150.

 

[colintrax]

I think I misread the 6200 as 5200 so I guess I need to clean my screen

I concede the rwd does seem to help, but hard to say how much as the engines are slightly different and the car companies usually over claim capability.

Problem is I do not know if dodge has fudged things more or if Ford has fudged things more

Rwd is better for towing because the trailer adds weight to the back not the front. As for towing with a unibody. The unibody needs a "frame" to give the hitch a spot to attach to and transfer the weight to the wheels. Both power and braking. This is why I don't see full size trucks going unibody. 12,000lb tow rating would make the unibody useless other than eliminating the extra height and body mounts. Which most truck owners want.
If you don't believe me look at a civic and then look at an avalanche.
Also, towing capacity is now standardized by SAE. So everyone does the same test