Did I just get 16+mpg?

[austinado16]

Just back from a 535mi round trip to the Los Angeles area and it's looking like 16 and change, maybe even into the 17's. I'm a little shocked, but I didn't use the entire tank, and the gauge is still reading about 4 gallons left.

What's blowing my mind is that normally I drive the 'burb 55-60 because otherwise, it's gets a solid 11mpg. We were hauling the daughter and some of her cross country teammates, so in order to keep up, with the coaches in 2 other school vans, I was running 70 average. The trip included quite a few meal and/or bathroom stops, and therefore, some pretty moderate accelerations back out onto the freeways. There was none of the stepping on an egg driving method that I usually drive it with.

A couple weeks ago I did a rebuild on the throttle body, which included replacing the fuel pressure regulator with an adjustable version. I've got the fuel pressure set at 12.8psi

If this thing is suddenly capable of 16-17 with a load of people and gear, at 70+, I'm kinda blown away.

 

[skysurfer]

I believe it. Mine got 16 mpg on a long trip when it was in stock trim but the lift, tires, and rack I installed killed that mileage big time.

 

[Jims86]

I got 17.5 last run, most at 70 mph....untill laytonville

 

[austinado16]

Laytonville!

Lived in Arcata for 11yrs. Know that run up and down the 101 like the back of my hand.

My figures are about 535mi on 30 gallons.........17.83mpg. That would be insane pushing this brick through the wind at 70mph.

 

[TheBlue'Burban]

My 87 2wd 350 surprised me with 17.5 with old plugs and wires when I first bought it.... I have been keeping receipts, need to do another check to see if it's still getting that. Certainly surprised the hell outta me!

 

[Green79Scottsdale]

With the extra 10-15 mph, you are probably putting your engine closer to your torque peak, and therefore it is not working as hard to maintain that speed. Hence, it is better on mpg. When I had my 01 Monte Carlo, I found I got better mpg by NOT babying it on take-offs and driving 75 mph of the freeway instead of 70. Just doing that improved my mileage by 2-4 mpg.

 

[Jims86]

Laytonville!

Lived in Arcata for 11yrs. Know that run up and down the 101 like the back of my hand.

My figures are about 535mi on 30 gallons.........17.83mpg. That would be insane pushing this brick through the wind at 70mph.

Yup, Arcata is where she is sitting now...in the trees above West End, and Aldergrove roads, ya know, the Renner station and the mill? ****, now I want a Bacon cheese burger from Toni's.

 

[89Suburban]

I might be making a short road trip in Silvy Saturday up the turnpike. I'm gonna try and see what she get's on the highway without the boat. Right now couple mile trips, around town with the boat, stop and go I am only getting 8 - 10 mpg. The '89 must have been getting 4 - 5 mpg because it definitely doubled going to Silvy.

 

[austinado16]

While I understand the torque curve and engine efficiency, this things got 3.42's and a 700R4, so it's only twisting at about 2,100rpm at 70ish (1,700rpm at 55). Max torque comes in at 2,800? Plus, let's not forget it's got the aerodynamics of 2 sheets of plywood.

But whatever the reason, I'm not complaining.

BTW, she rolled 284,000mi on this trip. Original engine. Original trans went to 234k.

Arcata, Arcata, Arcata.... I lived there from Oct'74-Dec'85. 6th grade thru 2-1/2yrs of college. Have a million great memories. We were just back there in July '12 on an 8 dayer, camping all the way up to Oregon Caves. Spent 2 days in Arcata/Eureka showing the daughter where I grew up. Prior to that, I hadn't been up there since Feb. '99.

 

[Jims86]

Well, not many live in Arcata, and have not heard of Ben Hurd's Christmas tree farm. Have you?

 

[austinado16]

Well, not many live in Arcata, and have not heard of Ben Hurd's Christmas tree farm. Have you?

Nope, but prior to a quick visit in July '12, I hadn't been up there since Feb '99.

 

[Jims86]

Nope, but prior to a quick visit in July '12, I hadn't been up there since Feb '99.

Ahh, ok. He has been up and running for 40 years.

 

[jux]

Good to hear you have improved fuel economy. I myself get about 16-18 mpg.

Interestingly, I get about 5+ mpg more now with a 350 than with the 4.3 that came originally in my truck. And that 4.3 had a rebuilt + tuned q-jet, I'm running an eddy in the 350.

 

[austinado16]

Ahh, ok. He has been up and running for 40 years.

Never heard of the place, but I wasn't "married-with-kids" so a place like that wouldn't have been on my radar. We always picked up a tree at the Safeway just down the street from the PD.

 

[cedens]

WOW!

I haven't tracked MPG's on my 82 since 1995 but that is better than my 10 2500HD which sucks about 15-16MPG with a mix of highway and back road driving