My friend and I are trying to go to visit his family, and they live in a rural part of Tennessee, their driveway is a very steep, mile long, loose gravel driveway. He has a manual 2003 Ford focus, which isn’t exactly the pinnacle of horse power. What is the cheapest/ most efficient way to make it up the driveway? Or do you think it could make it up their without any extra assistance?
Depends on what you mean by loose gravel. If it’s like, 12" thick pea gravel he might have a problem. If it’s just some gravel on top of dirt, and it’s not a mud mire when he goes through, he’ll probably be fine (depending on how “very steep” is defined)
If his car cannot for whatever reason make it up the driveway, the cheapest and most efficient solution is to park the car and walk.
If you have a problem it’ll be with traction, not horsepower. If these people have a phone, I’d just ask them what to expect.
Just drive there and try to get up the driveway. If you can’t make it, either walk up or call them to come get you. If your car can’t make it up the hill, I’m sure others before you had the same problem.
Because this car has FWD, you would actually get better traction by driving up that driveway in reverse. However, the length of the driveway probably precludes doing that.
You may just have to park the car and walk the rest of the way.
2003 Ford Focus horsepower ratings are 110 to 170 HP, depending on the engine. mid-1960’s era VW Beetles were around 40-50 HP. I drove the ranch’s 1966 VW Beetle as a hired hand on a cattle ranch in Colorado, up & down steep mountain dirt & gravel roads all day, everyday, with no problem. Your Ford’s power won’t be an issue. Traction, maybe. But not power.
There are some non-aggressive tire-cable-like strap-on contraptions I’ve seen people use for improved traction on lightly snow-covered roads on the way to ski resorts. But I doubt you’ll need them. If you need anything, it will probably be higher ground clearance, and in that event if all you have is the Focus, you’ll be walking up the last mile.
In Tennessee, C3 is commonly used in driveways. That is rock that is crushed to about 3/4" size. Once it is spread and compacted, it locks together. You won’t have any trouble.
If however, the driveway is brown, that would indicate A1 which is used in roadbeds. That is smooth gravel, 1/4" or larger in clay. It can be a problem if it is wet, but if dry, again no problem.
I think the car will make it without a problem. Heck, people live up there and must come and go to get groceries, household goods, more shine!!! They get in and out, but if you get stuck call them on your cel phone and granny (92 years old) can bring down her truck.
Here she comes now
Yosemite
Just try it. Go as far as you can and walk the rest of the way up…if need be. I’ve never had a problem with a steep gravel drive in my life whether driving a FWD or RWD. Slow and steady is the only way to go.
What do your friend’s family members drive? Do they find the need for special tires?
Maybe this:
Do you drive in snow? Just pretend it is a snowy hill, get a running start and don’t stop till you get to the top.
Because it is fwd, it may be worse driving up a very steep hill. Fwd cars can be very poor on hills. Good tires are a must, minimize the weight in the back seat and lastly if all else fails, back up the road. Fwd cars have gobs of traction backing up. For the entire mile, it should not be a problem if you get a run for the steepest parts. That’s what we do on our road. There are several shorter areas a fwd can not make, even in summer, if they drive too slowly and especially, if they stop.
It’s gravel covered and very steep in spots and all cars make it in if they don’t stop in the steepest areas and …drive real fast. 
slow and steady only works if it isn’t too steep. Momentum is your friend driving up hills. When you see the steeper areas, speed up before you hit them and don’t stop for anyone or anything…just kidding but you get the point. I really see no problem if you keep your speed up.
Used to back my Focus up my pretty steep driveway in the winter time,if you have a pull off, tell your freind to get you an “EZ GO” or golf cart to shuttle back and forth with
I think the OP has left the building.