Looking to buy used '90s Suburban, what combo gets best mpg? [Expired Topic]

Define "Decent"? for what it sounds like you want a suburban may not be the best choice. I am not aware of a V6 version but some of the other guys here will know better. If milage is such a big concern you may want to look at newer E85 compatable Burbs, I think (2002 or newer) or maybe a mini van. Of all the strengths of the suburbans milage is not necessarily one of them. The diesel guys may disagree but I get 10 mpg with my 95 and very happy with it. But I don't use it just to haul kids around, without a requirement for towing or hauling gear of some sort there is probably a better fit for you with a more fuel efficient vehicle.

Please note that my comments are ONLY because you seem to have a very high priority on gas milage. If that were not your primary issue then the suburban is the perferct kid hauler.

Looking to buy used '90s Suburban, what combo gets best mpg?

Most of my driving is city driving, and I would like to get 15 MPG or better in the city. Not sure if that's realistic, but something to shoot for.
My first concern is cost of the vehicle, then milage.
I'm looking for the best bang for the buck. I've had a minivan before, it was great, but I really like the look of the '92 and newer Suburban, the parts availabilty, and ease to work on. With the exception of fuel cost, it seems like it would have low operating cost.
I would like a good used vehicle for under $6k. I only drive between 6000-7000 miles a year, and the added cost of a better gas milage newer model would take a long time for the cost tradeoff to payoff.
What's the smallest V8 used on one of these? I think a 350 or 454 is what I've usually seen. Do they make one with a 305? Maybe I could find one that needs a motor, and install a 305. Assumming the original motor was a small block, a 305 would be an easy swap. Not sure if the engine management system would work going to a smaller motor. Any thoghts on this?

Thanks!

The smallest engine in recent history was the 305 V8 which was discontinued (in the Suburban) in 87. However, smaller is not always better.
A big, well designed, efficient that's not working hard usually will get better MPG in a large heavy vehicle than a smaller engine beating itself to death.
For example, Some guys with new 2500 Avalanches with the 8.1 litre V8 get up to 18MPG on the highway.

That said, there's no doubt in my mind that a diesel is the way to go. It will give you excellent mileage, much more power than a V6 (which you can't get anyway) or 305. If you're not a diesel guy, don't let it scare you. They run great, are extremely reliable (PMC cooling excepted, get a cooler kit) and get better mileage than any gasoline combo. Plus if you have a biodiesel dealer in your area, you can get even better prices, lower emissions, and do your patriotic duty to reduce foreign oil imports. ;')

If you went diesel, 96-98 is the way to go IMO. That or a pre 91 non turbo, but the turbo 6.5l is an all around good performer.
If you insist on gas, than look for a 96-99 350/5.7l gas model. In those, a 4x4 really doesn't cost you any significant MPG when you are not using it, and it's sure nice to have in bad weather. The older, pre 91 machines will use a little more fuel than the newer ones due to the older 4x4 system.
Whichever one you get, put synthetic oil/lube in it, a good air filter (like a K&N) and watch your tire pressures. A free flow exhaust, and computer chip upgrades can also improve mileage. Remember most mods meant for modest performance gains really just make an engine more efficient, and therefore, as long as you can keep your foot out of it, you will also get improved MPG.
My 99 Tahoe had a K&N filter/intake kit and it never got under 16 MPG no matter how hard I flogged it, and got as much as 20 MPG on a good day.

Good luck with your search and keep us posted on the results.

P.S. Diesel plus veggie kit = extreme cheap fuel.