I'm wondering why Interstate isn't working for you at 24 pt. Should do fine. How much text we talkin'?

At 24 pt even Interstate should work as body copy. No? Did you try it?

This sounds like signage.
How fast are your readers driving?

lol.

they are driving off a cliff and they want to put a billboard on the side of the cliff for them to read as they crash to the ground below.

oh, the copy is readable. its just that interstate was not developed to carry large amounts of copy...and if there is a font that is similar but more friendly towards large amounts of copy.

How much text is set in 24 pt?

I have set Interstate as headers with Baskerville before and it comes out looking great. It was identity work for a hotel, if that matters =)

full 8.5 x 11 page with .375" margin. i'm looking for this part of the piece to have a certain amount of tension. so i like the interstate (sans serif) for that with the small margins.

24 pt. could be right for the fine print on a parking lot towing sign, but even then that sounds pretty small. I can't think of a lot of places where 24 pt. type would be considered "body copy", but that's one. I remember doing a large copy-heavy park rules sign, but I think that got no smaller than 64 pt.

24 pt on a letter-sized page, AND headlines? That doesn't leave you with much space to work with.

i’m looking for this part of the piece to have a certain amount of tension

I would think that Interstate would make the perfect body text to add tension, precisely because it is NOT designed for text. But at 24 pt, you could use Hobo for body copy and it would still be workable.

ok sunshine. thanks for the hobo recommendation.

"...interstate was not developed to carry large amounts of copy..."
Large amounts of copy at 24 pt. for the chosen line length will work with the right leading and word space. There is a huge x-ht, generous counters and spacing. . . If I did anything to improve it for this purpose, I'd add long(er) descenders and perhaps an additional g, for when more leading was desired than these short descenders can 'take up', and for better recognition, respectively.

Or show me/us what you mean, because I think your 'certain amount of tension' is the kind of body text Interstate is famous for in 40 styles. :)

Cheers!