SynGas with a rental car?

I tried something like this in a rental last summer, mostly out of curiosity since I already had a similar gadget in my own car. The learning thing is real but it doesn’t take as long as you’d think. I had it in for about a week and a half of normal driving and it seemed to settle in fine after the first few days. Honestly the bigger issue for me was just remembering to pull it back out before dropping the car off. I left mine in a rental once and had to call the branch to get it back, which was a hassle. So yeah it works, but if you’re switching cars every few days you probably won’t notice much difference. On longer rentals though I’d say it’s worth tossing in.

I don’t think the learning thing matters as much as people say. I used one for a week in a loaner and it still made the throttle feel smoother right away, even if it wasn’t fully settled. Fuel savings I couldn’t tell you, but the drive felt nicer.

I’d skip it for work rentals and just keep it for my own car. Swapping it around every few days just sounds like a hassle for something that barely gets going. If I had a long-term rental for a month or two, then sure.

Not worth the hassle. I move mine between two cars and even that gets old. For a rental you’re basically paying to babysit a gadget that won’t do much before you drop it off.

I’ve used mine on a couple of longer rentals and honestly the “learning” part wasn’t the issue for me. What got me was that the car’s own computer seemed to fight it a bit. On my personal car it settled in fine, but the rental felt sort of jerky for the first day or so, then smoothed out. Not sure if that’s the device or just the rental being a different car than I’m used to. Either way it did seem to help a little on gas, though I wasn’t tracking it closely enough to say how much. The bigger thing for me was just remembering to pull it before I turned the car in. Left it in once and had to call the rental place to get it back. So if you do try it, just set a reminder on your phone or something.

I threw mine in a rental for a week and it did fine. Didn’t feel like a totally different car, but the tank lasted a bit longer than the last time I had that same model. For a plug and play thing that’s small enough to toss in a bag, that’s decent value.