Coil springs vs leaf

bhayden · 10-20-2006, 06:53 PM

A recent thread knocked the Tahoe (and I think 1/2T Subs) for having coil springs which gave that "soccer mom" ride. I'm not so sure coils have an inherently better ride than leaf springs. After all, old Caddies and Towncars have leaf spings). But having towed our trailer with a Tahoe and our Safari van (leaf springs) I can atest to the much more comfortable ride in the Tahoe but it's also a far more competent tow vehicle. How come?

Sure the bigger V8 engine makes all the difference in effortlessly cresting all the hills but just straight line stability was better with the Tahoe. The Tahoe has a 5" long wheelbase and is 10" longer overall. I'm guessing the rear overhang is about the same as there's more in front on the Tahoe. Anybody have a rule of thumb for the effect of wheelbase vs overhang?

Does the longer wheelbase trump the leaf springs?

FWIW, factory towing capacity on the Tahoe is 8,800# and 5,800# for the Safari. The Tahoe is also a 1000# heavier which I'm sure makes a big difference!

-Bernie

**overlander63** · 10-20-2006, 08:51 PM

Part of it is also the "sail effect" of the high sides on the van catching every breeze that blows across you. That and the weight of the engine and transmission being further forward on the Tahoe to balance the tongue weight.

SafeHarbor · 10-20-2006, 08:57 PM

Hi, Bernie,

I don't know about the Tahoe, but I think that leaf springs make better "overload" devices than coil springs. Maybe that's why they were normally found only back on "weight handling" axles. This is also true on modern trucks. All-around springs became a feature on Detroit iron sometime in the fifties.

Lamar

Lamar

Safari64 · 10-20-2006, 11:23 PM

Hey Bernie,

What kind of gas mileage do you get with the Tahoe (towing and alone)? I'm thinking about one as tow vehicle.

Has anyone towed a 22+ footer with a Dodge Durango?

I'm hunting for a mid sized, nice riding, non unibody SUV with (get this) decent gas mileage

, that will last 150K + miles, and that I can also use as Airstream tow vehicle.

Safari 64

**overlander63** · 10-21-2006, 07:06 AM

Fred, the brand-new Tahoe is supposed to get 18-20 mpg with its cylinder deactivation system. Those figures are non-towing, of course.
I towed an Argosy 20 with a Dakota for quite a while, the Durango is a similar drive train, but a shorter wheelbase. I have seen people towing fairly large travel trailers with them, but I don't think I would want to, because of the short wheelbase.

bhayden · 10-21-2006, 07:59 AM

The Tahoe is my mother-in-laws so I don't have really good data on the mileage. Not towing the best she's gotten (literally, driving like a little old lady) is 18mph. Not sure what we got towing but I'm guessing it was about the same as with our van meaning 12-13. The big difference is the Tahoe (2000) had only ~21 gallon tand vs the 27 in the van so you had to plan fuel stops more carefully.

Weight distributiion/engine placement I'd guess it farther forward on the van. That's probably part of the ride issue too. You're about sitting on the front axle with the van vs. closer to centered in the Tahoe. Sail effect isn't that much difference. Close to the same height and the Tahoe is longer. The extra 1000# I'd guess makes more difference. I'm sure it's a combination of all this stuff but it would be nice when evaluating a TV to have some rough formula (ROT) to weight the differences.

The only reason I can think of for the coils in the Tahoe are ride comfort. Other vehicles it's often packaging concerns (i.e. no room for one or the other type of suspension). Since they use leaf springs on the 3/4 and coil on the 1/2 it seems they could have gone either way. I'm guessing the coil set-up acually cost them more money.

-Bernie