lowering trucks?

[gotmehooked]

I have a 08 gmc sierra 1500 extended cab sitting on 265/70/17 tires, anyone know if lowering it would help out at all with fuel economy.

[Sven7]

It most likely would. It would probably be easier, though, to add an air dam and belly pan.

[d0sitmatr]

Originally Posted by gotmehooked

I have a 08 gmc sierra 1500 extended cab sitting on 265/70/17 tires, anyone know if lowering it would help out at all with fuel economy.

yes, I had a 99 ranger XLT that I lowered 2 inches in the front and I saw about a 1-2 mpg increase on the hwy. of course, it did nothing for city driving except to make it much better handling.
by lowering it, your presenting a smaller frontal area. but I dont know how much of an effect it will have on a full sized truck.

[aerohead]

Originally Posted by gotmehooked

I have a 08 gmc sierra 1500 extended cab sitting on 265/70/17 tires, anyone know if lowering it would help out at all with fuel economy.

Lowering gets you two birds with one stone:
*the small reduction in projected frontal area as already mentioned as some of the tires frontal area is reduced.
*then,the apparent fineness-ratio of the truck (length/height) is increased,always a benefit to production vehicles.

[kach22i]

I think lowering adversely affects payload ability.

[Floordford]

Id go lower if I was you. Then possibly look into grill block off.

[brucepick]

Build a full belly pan first, while it's up higher. Easy to crawl under and attach your panels. Then lower it if you want. Make the panel easily removable (maybe stainless screws instead of rivets for example) to make undercarriage work reasonable to do.

I think you'll get more gain from the belly pan than from lowering - just a guess. But after you lower it building the belly pan is much more of a PITA.

Find the lowest part of what's underneath - probably the rear diff - and build the belly pan at that level. So the pan won't need to go up and down to clear stuff. Just cut it away where it needs to clear the suspension arms.

Grill block off - definitely a good idea. And faster/easier to do than lowering or belly pan, I would think. I strongly recommend a ScanGauge or any digital engine temp gauge so you will know the coolant temp. A needle gauge doesn't really tell you much. The engineers designed it with enough CYA so you can probably tow a big trailer across the desert with a/c running - but when you start modding it, their CYA design isn't there any more.

[kach22i]

See the link in my signature below. A simple chin spoiler is good for couple of MPG hwy. My black truck in the photo sits higher than the tan S-10 in the foreground, something the previous owner did.

[gotmehooked]

I'm just wondering if lowering would affect hauling or handling on a truck this size. I definately am going to do the grill block. Does it need to be completely flush with the grill trim to be most effective or can it be recessed like the grill is now? As for the belly pan I need to crawl under and have a look to see what kind of fabrication I can do and how wide are they supposed to go; wide and as long as the vehicle is? Sorry for all the questions, new to the site and excited to squeeze some more mpgs from a full sized truck.

[BamZipPow]

My belly pan thread fer my Toyota T-100 truck. Goal was not to put in any holes in the vehicle and use only existing stock holes/fasteners.

Under belly pan... - Toyota Nation Forum : Toyota Car and Truck Forums