I am starting this thread to get ideas on how we can get better fuel economy with our Burbs. What have you done to get better fuel ecomomy with your Burb?
Now I know that 4x4 Burbs with 30 inch or more tires and 4:10 rear axles just wont get mileage but I'm talking about us folks that use them for daily drivers and are mostly stock. I just bought a 90 4x2 (700R4 & 350 TBI) Burb 1500 with 3:42's in the back and I'm getting 30 to 40 % less mileage that I was getting with my old 87 with the same powertrain and 3:08 gears. If I put a 2 1/2 or 3 inch dual exhaust with Flowmasters or something along that line will my mileage improve?

keep it tuned properly, don't use those so called improvment chemicals and keep it in good shape that is all you can do.
Dual exhaust will help on these beasts but don't expect any miracles. With my burb I average 10mpg city or highway... if yuo can get 12-15 then you are doing good.

I'm getting 15 on the highway with my 91 1500 4x4. 3:73 gears and 31 inch tires. Factory 3 inch single exhaust with Magnaflow muffler and stock cat. Oh yea 209,000 miles.

Bill

If you want to go all out, shove in a 6.2L diesel and then throw on a turbo. I've been thinking about doing that to a 67 Suburban I'm saving up for. My 85 diesel 'burb would get 19 mpg, but now it sits because the tranny is bad.

those #'s surprise me, I have a 99 3/4 bb burb that gets 16-17 at 75 empty and 11-14 at 65 towing depending on weight. and it has over 170,00 miles
I bought a 83 3/4 4x4 diesel burb 2 weeks ago, I have it for sale but if it doesn't go I am going to get it started. The P/O got 22 or so

I've got an '89 1/2ton 2wd with 133k miles, 3.73 and 32" tires and get about 15-16 mpg highway going 70-75.

I have an '86 3/4 ton 4x4 with the 350, 4bbl, manual transmission, and dual exhaust. Everything stock except I put in the K&N air filter and am running Mobil One oil. I get 12-14 mpg.

of course a 350 will get 12-17 mpg but our 454s will get worse... Deisels generally get slightly better mileage but when regular is at $2.99 and diesel is at $3.20 it may all end up equaling out cost-wise

My '87 Suburban 4x4, 31x10.50x15's, 350 .040 over, headers, dual flowmaster 2 1/2" exhaust, TBI spacer, 3.71 gears, TH700r4 i get 10 in town, and about 12-14 on highway. Before i destroyed the stock motor i was gettin 12 in town and 16-17 on highway.

Anyone Know how much of an improvement that headers on a smallblock will give you?
Thanks
Shane

Edit on SWB 1985 4x4 Silverado p/u

QUOTE [Anyone Know how much of an improvement that headers on a smallblock will give you? ] QUOTE


One or two more MPG . Of course other things effect the final results . I have seen guys get no change in milage by adding headers ..

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Put it in neutral and turn it off when going down hills. Start it up and put'r in drive when you need to accellerate. With all the money you save in gas, you can buy a new starter.

Down here in New Zealand fuel is 6.8 $ per gal so that was hitting the back pocket a bit to hard so I had it put on LPG and that is the best move I ever did as my sub is my eveyday car 60 miles a day it only costs me 37.5 $ a week :-}

so what's involved in putting on LPG?? for folks in the US, is that what they sell in some US stations??

GM motors like the RPM range around 2100 to 2500. That is where they operate best and the economy should be centered around the optimim operating range. If you are geared to high and your RPMs are lower, then it will impact your driving, especially if there are hills and curves involved. This takes into account for the use of Cruise (whether or not it has to kick down a lot to keep speed), the general acceleration power consumption, (high gears cause a lot of energy to be used up just to get to speed). The use of tall tires is great on highways, if they are flat, but end up the same as high gears on hilly roads or in cities.
My son's truck had 3.08 gears with a 700R4 tranny and the 1900 RPM ws killing his gas mileage. We went to a 3.73 gear ratio and picked up two miles per gallon. Just a thought to pursue.

Look at friction reducing fluids such as Synthetic lubricants (Amsoil, Energy Release, or Royal Purple), they do work, if not just in adding life to the vehicle. Do a good tune up on the motor, use a Multi-spark ignition system to get a complete burn in the cylinder (don't waste any ounce of fuel), do the fresh air in and bad exhaust out program (update air intake and exhaust) Headers will add performance to your vehicle, the mileage may not increase, but it will help other things do their job better---in the end getting a better economy. The manufacturers don't have to build it to optimum performance, they just have to build it. I put electric fans on my 91 Silverado, and took off the factory installed fan and fan clutch, it seems to have helped the MPG a little.

any one running throttle body spacer on there tbi 350. just wondering if there any help at all like they advertise or just a waste of $75

I've heard that spacers can help or hurt/have no impact on an engine... supposedly depends on a lot of factors... but I would think we can draw conclusions on stock 350tbi setups... I don't have one so can't tell you my experience...

I have an Airaide TBI spacer on my 5.7, 91 Silverado. It did not make the actual fuel economy change as much as it changed the low end torque on the engine, which makes it accelerate easier. That in itself ,is a definite improvement on the economy. It was a great investment for the change in the torque. I would say that it was worth the $70.00.

I also later added a MSD multi-spark unit, coil, and plug wires; they were worth an improvement in horsepower and fuel efficiency. The biggest change came when I took the fan and fan clutch assembly off of the water pump and put on two electric fans. This made about a 1.5 MPG change in my overall driving. The motor runs smoother and idles better than before.

THis is what I live by. Quit driving. And only drive when there is a potential to earn money or eat and the end of the ride. ok

When i get some time....i'm going to mod my tbi pressure regulator and see what i get out of it. If you go to thirdgen.org...register....and do a search under VFPR you'll find a nice 3 page post on converting the fuel pressure regulator to a big block vacum operated unit and a new spring and vacum delay valve from top down solutions....everyone seems to agree the swap has netted mileage gains...i'm still with out an O/D in the chalet but its fun to keep messing with her until you can't get no more. Remember an 02 sensor doesn't last forever...they get lazy...and that lag time the ecm see's equates to lost fuel mileage....



DW