Suburban mpg

[Ziegelsteinfaust]

As my Durango causes me more pain, and honestly I wont put another dime into it. I am looking to replace it with another primary DD, and keep my C10 as a back up/fun vehicle.

I just found a 1983 C20 Suburban with a gas engine in a diesel titled vehicle. So it has the easy option of better motors for drivibility with fuel injection. Or just swap in a Cummins 6bt if I go crazy. It supposedly runs fine now, but it's a generic Edelbrock carb'd 350. So maybe 10/12 city, and 15 mpg highway at best.

So as I have said before I would love to have a matching Crew or Suburban for my C10. That way only 1 set of keys. As I exemplify laziness. Although the 69 Nova I am looking at probably can use the same keys too.

So for my DD mpg is not that a big issue. I have a 4 day work week with a daily total of 16-20 miles round trip. Although improving gas mileage to match the Durango would be very nice. The Durangos 3.92 gears really help with city mpg as I really don't jump on the freeway in my day to day life.

Where I am worried about mpg is longer drives. Like when I go get my son, visit family, or go on road trips. It's not uncommon to rack up 250+ miles in a weekend doing things, or a road trip for 500+ is easy. I love the idea of a Suburban for the idea of sleeping in the back of it.

So if I dial in the Burb for mpg. Like lowering it, swapping in a lighter rear axle, and tires. Would 20-22 highway be out of the question with a nice 4.8/5.3 LS with full bolt ons?

I would like the 4.3 LV3 direct injection V6 swap, but those are costing mint. Yet in my 2018 Silverado crew cab. It would get 25/27 mpg highway, and it moved the big girl nicely. Plus towing didn't seem to stress it much in the factory configuration.

The Nova's I am looking at are both 4 doors which suits my needs, and would be easy to drive. Hell I probably could get 30 highway with a well designed V8 swap, and just enjoy that. Rather LS or a old school gen2 LT1 I have parts for.

So has anyone done a LS swapped Suburban, and thought it was as good as a new one? Or felt like it never meet expectations driving wise.

[gerryeric]

87 R10 Suburban 6.0 LS 4L80, 3.42 rear end. Did the swap Nov of 21, 41000 miles since swap (yes 41000, not a typo). 12 mpg around town consistent 15MPG on trips. Do not regret getting rid of 5.7 TBI (that I put about 20,000 miles on preswap)

[Ziegelsteinfaust]

Are you running big wheels or a large cam?

[SBTork]

I had a 1985 C10 Suburban, lowered on air with a stock 5.3/4L60 and 3.42 gears. Around town I got 17-18 with a heavy foot. On the highway I consistently averaged 22-24.

[gerryeric]

Originally Posted by Ziegelsteinfaust

Are you running big wheels or a large cam?

Yes, 20" detroit steel Delrays and a Brian Tooley stage 3 cam