From this link we know that Tidal force is defined like so:
In celestial mechanics, the expression tidal force can refer to a situation in which a body or material (for example, tidal water) is mainly under the gravitational influence of a second body (for example, the Earth), but is also perturbed by the gravitational effects of a third body (for example, the Moon). The perturbing force is sometimes in such cases called a tidal force (for example, the perturbing force on the Moon): it is the difference between the force exerted by the third body on the second and the force exerted by the third body on the first.
So, straight off the bat we see the Earth-Moon example. Keep in mind that the Earth is many times more massive than the Moon, and the Moon is many times more massive than Iapetus.
So let's look at some basic info about Iapetus that is relevant to your question using info from here. The surface-level gravity on Iapetus is 0.223 m/s2, or roughly 0.2 Earth Gs. Escape velocity is also pretty low - 0.573 km/s, or 573 m/s (Earth's escape velocity is 11.186 km/s). This means that although you can't just jump and fly off into space, it won't take much. In fact, if you're in a car-shaped rocket on a flat, race-track like patch of land (approximately tangent to the overall curvature of Iapetus), you could very likely accelerate right off the moon on the end of the track. The fastest car on Earth is the Hennessey Venom F5, at 301 miles per hour (or 484.413 km/h). But this is on Earth, where air-friction is a thing and let's not forget the mass of the car, which is a large part of why a car travels fast at all (and I'm not even going to talk about downforce). So, if we instead attach a rocket at the end of this vehicle (not even a massive one, just like the kind used in missiles), we'll be off-world in no time.
TLDR: Iapetus is too small to affect anything even the size of a car with tidal forces. Iapetus does, however experience tidal forces relative to Saturn. If you want to get needlessly technical about definitions, everything has a tidal force on everything because gravity affects objects even at infinity, hence there must be some perturbations - just not any noticeable ones. I know most of my answer didn't even deal with tidal forces, but perhaps the info I gave you will spark other ideas. I hope this helps!
Edit: @Hypnosifl pointed out that you were looking for info on a moon LIKE Iapetus, but not actually Iapetus, specifically if it has a greater mass. More specifically, we're talking about a planet like Iapetus that has the gravity of Earth somehow. This is given by the equation:
g = GM/r2
Now g here is equal to one of our Gs (9.8 m/s^2), but r=735 km. With some quick maths, M must be equal to: 7.9373388306×1022 kg. This is no moon at all, and must be made completely of some unrealistically dense material! If it isn't a neutron star, it must be spinning really fast, so fast that it's tearing itself apart, and nothing could possibly last long on its surface, regardless of the 1G it has. That kind of eliminates the question of tidal forces or anything. An Iapetus-sized that has such a high value of G is pretty unrealistic, even in scifi. Let's assume it's ridiculously dense as described in the comment. At this point I'd like someone who knows better to please chip in as to my knowledge, I know that tidal forces won't be what you need to worry about, but I know what it would be.