Purchased for my RV's 2nd annual treatment. I add 4-cans of BG to the 80-gal fuel tank of my motorhome, then drive the interstates. While driving, I run the on-board generator, which fuels from the same tank as the main V-10 engine. I do this annually because of my usage pattern: from March-Nov the RV gets used monthly, (average 800-mi/month), then stored with minimal use for winter when I add a fuel stabilizer. Do I think 44K works? Well, it doesn't hurt 😉. I can't tell much-if-any difference in fuel mileage on the 2011 fuel-injected Ford V-10 (35,500-miles on odometer), but it starts easily and runs smoothly each and every time, knock-on-wood. The generator is another story. It is a 2011 Onan 7kW V-twin carbureted design. For whatever reason, it can be hard to start. Until 44K. After last year's treatment, it became noticeably easier to start and settle into a smooth idle. It's temperamental ways returned after winter storage last year, but after this years 2nd treatment it starts easily and runs smoothly. Since the only difference is the 44K in the fuel, I'll give credit to this stuff and keep using it annually. Something is working on the generator, so I bet it's working in the V-10.

Of all the fuel system cleaner products I have tried, this is by far the one that make the most noticeable difference. To be fair, I have not try all of the fuel system cleaner out on the market (the not highly recommended ones). I figure is just a waste of my money so I only tried the most highly recommended ones. Have only tried Lucas, Chevron Techron, and Royal Purple Fuel system cleaner products. To be honest, I never really feel any big difference until I tried BG 44k. And this is on my 2 cars that are still less than 70k miles and have been using only Chevron gas since brand new of the car dealer lot. Even after that still can feel the difference, that says a lot. Is not 100% perfect though, in time I am sure somebody will come up something even better, but here is my pros and cons from my experience and opinion.

Pros:
Engine right smoother like brand new car
Engine has more power
Better acceleration
Rough idle gone ( in my case I don't really feel it on my car, but after using it, I can still feel the difference of less vibration from idle).

Cons:
Only 1, gas mileage hasn't improve. Yea my 2 cars gas mileage has not improve 1 bit, but I also suspect it might be something else. Gas mileage had definitely gotten slightly worse since when they are brand new. I used this product even after new sets of tires, oil change (both engine & transmission), tune up (spark plugs, air filter, etc). Pretty much everything I can think of. I am not an unreasonable guy, just have to accept the fact that there will always be a certain thing about car you can never restore to brand new condition after they are used. Gas mileage lost is a problem has something to do with normal age, tear and wear of the car engine or mechanical parts.

So that's why I am still giving this product a 5* simply because I have not run onto a product as good or better than this one yet.

As soon as it arrived, I used it right away putting it on almost 1/4gas, idle for 15mins and drove around for 30mins. I feel the difference no rough idling no shaking at 2000rpm or at change 1st to 2nd gear, I tried several well known brand but definitely I will stick with BG 44k

Great stuff to use prior to tune up

This product is hands down the best out there! I have been using it for over 3 decades now. Just a reminder to use a high octane gas after putting it in your fuel tank, to get optimal results.