Nobody warned me about the MPGs on these square bodies!

[Ricko1966]

The baffled tank is 100% the solution. When I installed my Holley sniper I plumbed my 87 baffled tank with new lines and installed an inline pump on the inside of the frame rail. I did all the work with supplies found in the sniper master kit... 5ish years later everything still works and I've never run out of fuel. Ive got the tank fairly low many times.

I would think,if you could still find it,a list and some basic direction as to what you used and did.Would be helpful to a lot of people. I have no expierience with sniper,just plenty of expierience with OE systems.I can tell them what the factory did because that's what I know. I see people with sniper questions so often that I think a list would be helpful. Maybe even start a dedicated thread for sniper.Have an awesome day.

 

[WFarm]

75 Blazer with 454, TH350, NP203 full time 4WD and 3.73 gears, gets less than 10 I’m sure. Haven’t calculated it but as someone else mentioned the “Smiles per mile” is way up there.

My other ride is a Saturn V rocket. What a blast, no pun intended. It gets less than 6 inches per gallon, first stage burns around 20 tons a second of Super Premium.

 

[Bennyt]

My '89 K5 (350 Tbi, 700r4) on 35's got 12-14. I added a Vortech S-trim with a big pulley so around 4-5 psi boost and the gas mileage actually went up 1 mpg consistently. I think because it no longer had to "lug" when accelerating. I believe the truck dyno'd right around 225 rwhp with the Vortech. I think 175 was the baseline.

 

[chief_shotts]

That’s good to know ! They were twice that when I was lookin (but that was in the middle of the Biden inflation apocalypse) compared to $90 for a nonbaffled tanks and Holly said it didn’t need to be baffled so why spend the money. I’m not even sure if the baffle would fix the problem honestly. Still could be a pickup issue.

Check out what I said on post 59.

 

[Frankenchevy]

I’ve had the sniper and now have pro flow 4. 1987 specter baffled tanks and 96-99 vortec pump that puts out around 60psi and never have had fuel supply related issues.

I think it was about $160 per side for tanks and pumps.

 

[Ricko1966]

I’ve had the sniper and now have pro flow 4. 1987 specter baffled tanks and 96-99 vortec pump that puts out around 60psi and never have had fuel supply related issues.

I think it was about $160 per side for tanks and pumps.

This is what I tell people to use,for some reason they still seem to think hydramat and Holley pumps are better and cheaper. Twice in the last month or less.

 

[ghopp24]

Who cares Abt fuel mileage, just enjoy having a real truck.....

 

[TotalyHucked]

My truck got 12 when I bought it. 12 on the hwy, 12 on backroads at steady 55, 12 sitting in the driveway. 305 with 2 dead holes, T350C, 2.73. Shortbed/2wd. With the cammed 5.3/4L65/3.90 and the bigger cammed 5.3/T56/3.90 get ~13-14 around town and 18-24mpg hwy depending on how fast I'm running

 

[CheemsK1500]

My ‘85 C10 (q jet equipped 350, 350C transmission, and 3:08 rear end) can get 12ish mpg when I drive in a tame, civilized manner. If I stuck to highway only, I could probably get a consistent 13-14 mpg.

 

[BadBowtie]

you should be doing better than 8mpg with an OD transmission (assuming you have some highway time mixed in). my 1990 burb with 33s, 700r4, 350tbi will pull down 13ish on the highway at ~75mph unless i am fighting wind. around town it does 10.5ish.

That 'Burban of yours has TBI, fuel injection, and sits way down lower too. What axle ratio is in the Suburban, 3.42?? That's comparing apples to grapefruit.

 

[BadBowtie]

Unfortunately with my short bed I’m stuck with the 16 gallon tanks! The 20s would be much nicer.

When you get both tanks working again, you will be fine. Keep a Jerry Can in the bed too as back-up.

 

[Ricko1966]

Who cares Abt fuel mileage, just enjoy having a real truck.....

I can't enjoy my truck if I can't afford the gas to drive it.

 

[Terlingueno]

There is supposed to be this sticker on your engine...

You must be registered for see images attach

 

[Lorrie]

1989 3/4 ton Suburban, 350 engine with 70,000 miles.
I put approximately 3,500 miles on her annually. I also keep a spreadsheet that tracks mph as well as a maintenance log. 10 mpg is my average - sometimes more, sometimes less. If I'm only driving short distances it is less. When I tow my 18' vintage trailer (approx. 4,500 dry weight, so probably closer to 6,000 fully loaded) I only get about 8 mpg. I bought her in January 1999 and haven't had a car payment since 2001!!!

 

[xm20k]

Did the math for the C10 I'm at 298mi on 50 gallons of 93 at $4 per gallon puts me at 5.96 miles per gallon and about $200 thus far. Pretty much right in the middle of my 5-7 estimate.

$200 in the ranger of 87 would be 67 gallons and about 1200 miles.