SPEEDYTRANSAM1996

iTrader: (37)

92 blazer k1500 tbi horrible on gas. Has a Flowmaster on it and lifted with 15" rims / 31". Not sure of the gear in it but im getting like 10mpg on this beast . I did read somewhere about putting 327 heads on it. Looking for a 1day job under $1000 on the high end but would like if possible to keep as cheap as possible.
Thanks

NewOrleansLT1

Did you try the sbc section?

bowtienut

iTrader: (1)

About the only cost-effective thing you can do, besides keeping it in a good state of tune, is to bump the base timing up as far as the fuel you're using will tolerate under all operating conditions.
No, 327 heads will do nothing for you.
Since it's lifted, highway mileage is always gonna suck.

hrcslam

Suspension drop (I gained 3-4mpg highway doing a 4/6 drop on my Suburban). Smaller tires (I lost 3mpg going with 22" wheels with 33" tires from stock). E-fans (I gained 2mpg hwy doing E-fans on my Suburban).

Or buy a Honda Civic, Saturn Ion, Cobalt, or even an S10.

SPEEDYTRANSAM1996

iTrader: (37)

Thanks for your responses and the car is mostly city driving. As for gas , i use 87.

SPEEDYTRANSAM1996

iTrader: (37)

Wow , 2mpg with 22 from stock.... Damn , so what do you recommend on rim / tire size because i do plan to drop 4 inches sinces it got a 4-6 inch lift on it now from previous owner and only having it now for 2 wks

SPEEDYTRANSAM1996

iTrader: (37)

1992 blazer k1500 and i am not putting that garbage *** gas in this beast , only BP

bufmatmuslepants

iTrader: (3)

The TBI is like a 2 barrel carb, it's not efficient for getting the right amount if fuel to each cylinder. TBI has an advantage on cold startup over a carb and that's about it for fuel use. If you want better mpg and to not spend a lot of cash, get a junkyard 5.3 with all wiring and swap that in with your 700r4/4l60. You can find a complete 5.3 for $600, and use the rest on exhaust and mounts. You are NEVER going to get anywhere near the mpg out of a TBI as you would from a real multi port fuel injection system.

bowtienut

iTrader: (1)

I forgot about efans (Thanks hrcslam).
Good for about 1/2 mpg, city and hwy.

ahritchie

iTrader: (1)

This isn't the TBI section....swap it for a LT1

hrcslam

A 4 in drop drop from where you're at might gain you 1mpg, maybe. Your truck is pretty high, and lowering it 4 inches from where it's at will only cover another 4in of tire exposure to the wind. The dirty air under the truck will still be poor and a lot of tire will still be in the wind. When I lowered mine, it was from stock (4x4) and I took it way down (the tires were 32.6" tall and would sit about 1/2" away from the fender, pic below for reference).

The 22's killed my MPG. If you want to keep the truck lifted/4x4 look, I'd stick with 15's or 16's for wheels and keep the section width as narrow as you want (225's were stock as the base option for that Blazer) and are comfortable with. You want to reduce the amount of tire in the wind, how much air goes under the vehicle, how much rotating mass you have, and how much tire contact patch there is. If you want to go a lot lower, like my Suburban low. I'd go with 17-18's with some 225-255 section width tires and try and keep the overall diameter below 27 inches (speedometer adjustment needed). All of these things are things that make a 1992 K5 Blazer, not a K5 Blazer.

The Electric cooling fan will help, noticeably. But, you want to make sure you adjust it correctly so it turns off on the highway. Basically, find what temps the truck likes while it's cruising down the highway and turn the fan controller to a temp slightly higher than that; mine was 195ish. Also, you want to make sure at least 1 fan turns on with the A/C. I ended up installing 3 fans, 2 pullers for the radiator and 1 pusher for the condenser. The condenser fan was run off a relay and signaled by the clutch signal, if the A/C was on that one fan was on. It didn't turn off on the highway though, it was also a smaller fan the the two radiator fans.

For parts, I'd use a dual fan controller from Orielly's (Hayden Dual fan controller with Temp sensor P/N: 3647) for $35, that's what I used on my Suburban (and my Camaro before I started tuning and also on my Brothers BMW for his conversion) and never had an issue with it working. For fans, look at stock GMT800 fans (NBS Trucks) or even the F-Body LT1/LS1 fans (they flow some serious air). The truck fans may fit a bit better than the LT1/LS1 fans though. And a very nice perk is the added elbow room to the front of the truck by removing the clutch fan and it's shroud. Plus the water pump becomes really easy to change after that (no special tools!).

Doing a 5.3 swap will help, and I hear they are pretty easy to boot! You need engine mounts, a trans plate spacer, and exhaust manifolds, plus a new harness. From last I gathered, you could do it for less than $3K if you do the work yourself and some savy shopping. The LSx motors are way more efficient than the TBI's for sure, plus more power. My 2001 Suburban would get 18-20mpg highway, my best tank was 23mpg all highway through West Texas and that was with the 22's.

Honestly where you're at, you could do all of these things (minus the 5.3L swap and a huge suspension drop) and gain 1 mpg. Is it worth it? Your biggest killer of efficiency is the truck's height. Then it's size. Then it's shape. Then the wheel/tire size. Then the Engine. Then Accessories. You would end up spending less getting a ZX6r as a gas mileage saver than what you'd put into the truck to save money at the pump. And the Ninja would be fun as all hell to drive while still getting 40+mpg.

ahritchie

iTrader: (1)

At current (lowest gas prices in over a decade) it would take several years of and 10's of thousands of miles driving to get "paid back" the potential savings in gas (unless gas prices go way up, not likely any time soon). Better off to just invest that money to buy gas down the road, or just buy more gas! Or use that $1000 for a 4 banger beater that gets 30 MPG.

NewOrleansLT1

Swap an L31 Vortec in it..

SPEEDYTRANSAM1996

iTrader: (37)

Hrcslam , thanks for all the logical **** you've said , really appreciate it bro. Also , the GAS is this low all the time , election session its always low. Best believe prices will be back in the high 3's ... thank you all !!

bufmatmuslepants

iTrader: (3)

The gmt400s have the aerodynamics of a washing machine, they are not going to slice through the air on the highway like a gmt800. Pizza cutter tires, a low front air dam and lowering the truck to stock will help, but around town you are screwed with TBI. My 6000 lb 00 burb does 15 city with the 5.3, and 15 highway with 4.10s.

hrcslam

The GMT800s have better aerodynamics, but they hardly slice through the wind. Its still a big 2 box with flat fronts, a large grill and big panel gaps. The 5.3 is a huge step up in power and efficiency over the TBI.

I agree, around town there's nothing that can be done except using less of the right pedal.

I'd say K5 that K5 and get something smaller for fuel economy (Camaro/Firebird??).

ahritchie

iTrader: (1)

Well US oil production is at 43 year highs, storage levels at highest levels ever, but I'm sure that's just a coincidence since it's election year.

waltsfastz

iTrader: (4)

I had a 92 K1500 I drove 40 minutes each way to work back i n the day. Mine would junk an O2 sensor every couple years. I could always tell by the fuel mileage going to hill. It never would give a trouble code but would start running rich. Its worth a try and see

MuhThugga

Spend the $800-$1000 on a Saturn.

HellTeeOne

Since a stock 1992 K5 Blazer does about 13 mpg, a lifted one with oversized tires getting 10 sounds about right. Folks regularly underestimate how much a lift and oversized tires will kill mileage on light trucks.

Best thing you can do is put it back to stock wheel/tire/chassis specs, free-flowing induction, headers/exhaust and a good tune up. You might see 15-16 under a light foot if you did all that.