86 Suburban- anything that can be done?

[jazzie604]

My guesses: an easy mod would be to clean up the under carriage. Im sure that thing is riding high and dirty. Some belly pans should be really easy to fab.

for the truly adventurous, convert the truck to a turbo diesel, and then convert that to run on vegetable oil. if you have to make several service calls a day, you can let that thing idle all day on vegtable oil cheaper that it is currently running on gas. I think anyone that is in a delivery or road based service really needs to consider this mod. For people that drive less than 15-20 minutes at a time it is not efficient(due to warm up and flush out time) but any longer than that and it is worth considering. And, depending on what you upgrade to, you may actually be able to run an exhaust system that is also cleaner than your current setup. get cracking!!

[festivaWES]

I'm not trying to give you the wrong advice, but could you just sell it? I believe switching to a vehicle that gets better gas mileage will save you tons more money in the long run. You can still get a hold of a midsized suv or small truck to haul things and still achieve 25 mpg easy.

[instarx]

4 x 4, hmmm. I bet you have wide, aggressive tread tires. My G30 diesel van lost 3-4 mpg (18+ to 15) just from switching to mildly aggressive tread tires from highway treads, and they were not even wide.

I'd bet money that the most bang for improving your mileage is in your tires. Skinny, smooth tread, high inflation pressure.

Although not a mileage-improving suggestion, you can use less fuel by letting a GPS calculate the most efficient order of your stops and the shortest route between them. Many GPS will do this and you can EASILY save 10-20% fuel by driving most efficient route. I think route-planning by GPS is the most under-appreciated fuel saving technique around. Few people even realize GPS do that.

[rykoala]

Thank you so much for all the replies. I know that the possibilities with this thing are limited. I *am* trying to get a different vehicle for my work so that I can save fuel etc, but I'm trying to see what's possible in the mean time.

Thanks again

[shawn]

You can get mpg's out of a suburban, I have an 86 3/4 ton I get 15.8 mpg and it is carburated.

If you have a th350 or a th400 you have pretty low gears in the rear ends. Run a taller tire on the highway you will notice a huge diffrence. You probably have 4.10's or 4.11's run a 33'' to 37'' tall tire to keep your rpm's down this will save you alot.

Run a good carb like an edlelbrock 750 and intake, run same brand for best results, also run an offroad cam to keep the motor torqy, you need bottom end more than top end unless your racing.

Put race plug wires on 8.8mm that makes a huge diffrence, running high performance coil, wires, and ignition make huge improvements.

Most of this that is genral stuff that will need to be replaced anyway. Best advice don't cheap out on parts, It'll cost you in the long run.

Don't let anybody fool you a suburban is great overall rig if you set it up right.

[shovel]

Linky

Fiberglass hood/fender conversion to the newer, possibly a little more aerodynamic nose? Maybe you can find someone who makes a full one-piece tilt up front end, lighter than all that steel and a little slipperier.

Definitely look into smoothing your underbody aero... even with a pair of solid axles you should be able to clean things up a little.

FWIW, my sister's '91 Benz has plastic aero covers on the bottom of its suspension control arms... they appear to serve no other purpose. I'm sure it's as much for quietness as for efficiency, but in my opinion it continues to prove there's merit in underbody aero, even on bricks.

[Frank Lee]

Yeah, don't be fooled! 15 mpg is AWESOME!!!