Fuel economy of 7.4L (454) powered 3/4 ton suburban

[slowmover]

3.73 in my Dodge. 3.54 in my Dads 2500 Suburban. I wouldn’t want less unless it was the effective OD ratio.

In the 4,700-lb Chrysler (with driver), 3.23 wasn’t really “enough”. Not as a tow vehicle. Sure, it’d hit 150-mph, but . . .

3.42 was my idea of ideal, but illness put an end to the whole thing.

3.23 wasn’t bad, per se, as towing rpm was just below peak torque. That’s an ideal to maintain. Motor lives a good long life that way.

A great tow vehicle engine features high cylinder pressure. There’s not a HP substitute in regards MPG. Gearing is the answer.

(Besides, it’s a 454. About 2/3 of a real big block. Wrong architecture and lacking structural strength. A motor for a go-fast car; not a truck. The RB Chrysler was in Armored Personnel Carriers, 35,000-lb freight trucks and running natural gas pipelines. We’d ease around the Ford and GM motorhomes in the 1970s on the way up La Veta Pass. They’d have to have a wrecker pull them over the summit as they’d wheeze out. Same was true in racing them dead stock. They needed the race to be over early.

So you just tell folks, “hey, it’s a cheap-to-make Chevy motor” (which is perfectly true). The burden is that it’s in a pickup versus being in an Impala.

FE will be about planned use. Not otherwise. The relation between Average MPH and Average MPG tells the story. That takes an engine hour meter plus logging runs. (Meaning, if anyone, you da man)

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