The RainX company claims their windshield coating lasts approximately 3 months. This is probably only true under the most ideal conditions based on my personal experience. Having used it personally for many years, what I’ve observed is closer to a single month of effectiveness before it begins to need reapplication.
RainX rain repellent has been around a long time and other manufacturers have come out with superhydrophobic rain repellents that work better and last longer. Gtechniq G1 is the best rain repellent we found. Gtechniq claims it lasts up to 2 years. We’ve found effectiveness to be a little over a year before needing to be reapplied. Even though we haven’t seen it hit the 2 year mark, it’s a lot better than my personal experience with RainX of only 1 month.
Gtechniq G1 is incredible but it is quite a bit more expensive than RainX. If you want a choice that performs better than RainX but costs less than G1 you should check out Aquapel.
I live in the hot and humid southeastern United States where rain is fairly common. We’re not the rainiest area of the country but we get our fair share. Due to this you can’t consider where I live to be ideal conditions for increasing the longevity of the RainX windshield coating.
The rainier your environment, the more you need a long lasting hydrophobic windscreen coating. Keep reading to learn more about the benefits of hydrophobic coatings and why Gtechniq G1 and Aquapel are far better options than RainX.
RainX and windshield wipers
RainX lasts longer when it isn’t rained on. It will also last substantially longer if you don’t use your windshield wipers. Your wipers will rub away the coating faster. Parking out of the elements in a garage or car port will also increase its life expectancy.
When RainX begins to fail it seems to tend to do so directly in your line of sight. This is due to the use of windshield wipers since wipers are focused on clearing where you need to see. This may not be your experience but it will fail more quickly where your wipers have the most pressure applied.
Avoiding using your wipers is possible with hydrophobic coatings like RainX but I have found it difficult to never use them at all. When sitting still RainX doesn’t do a good job of improving visibility through your windows unless the rain is substantial. The reason is it causes water to bead and for the water to run off the glass it needs large enough droplets to run off due to gravity or the airflow of driving. Lighter rain or mist will still cling to your glass and obstruct your vision. This may sound like a minor inconvenience but in truth it is more frequent of a problem than you might realize.
The aerodynamics of your car or truck will determine how practical not using your wipers will be. The more aerodynamic your vehicle is the less effective speed will be at blowing rain off of your windscreen. Windshield wipers are less necessary the faster you’re driving. The force of air flowing over your vehicle will force the water to flow off the glass.
A truck with a more vertically oriented windshield will have more wind force applied at lower speeds than the more laidback windshield of a sports car. A sports car will need to go faster to have the pressure of the wind help blow the rain off the glass.
I’ve typically driven more aerodynamic cars and have found that I need to use my wipers some in stop-and-go traffic when using RainX. This is especially true when the rain is more of a light mist or sprinkle. The heavier the rain the more easily it will blow off the windshield. Even a light misting will easily blow off the glass at interstate speeds though.
The good news is that when RainX is doing its job well the rain will bead on your glass as opposed to creating a wavy and blurry image through your windshield. Even when there is still a good bit of water on your glass it is usually easier to see out through the beads than through an uncoated windscreen.
Other benefits of hydrophobic glass coatings
Products like RainX and Gtechniq G1 are primarily for improving visibility in the rain. That isn’t the only benefit however. Similar to wax and other paint coatings, RainX and G1 can help protect your glass. They will also make it easier to clean.
Your glass will accumulate road grime and other stuck on debris over time. Much of this can easily be cleaned away during a good wash but some of it will remain behind. Hydrophobic coatings make it difficult for road grime and other contaminants to stick to your windshield and will more easily be removed during a wash. This will help prevent grime from embedding or getting dragged across the glass by your wipers and causing scratches.
Hydrophobic glass coatings will also keep your wiper blades in good shape longer. This is because your wipers won’t be swiping across a sandpaper-like finish of embedded road debris.
Rain repellents will also help make removing frost, road salt, and snow during the winter. Additionally, insects smeared on your windscreen will be much easier to remove.
Is RainX bad for your windshield?
No, however it can prove frustrating. Its short lifespan is the main source of frustration. The need to reapply so frequently to address spots on your windshield that have lost effectiveness is quite annoying.
The other problem that can plague RainX as well as other hydrophobic glass coatings is windshield wiper chatter. Windshield wiper chatter is exactly as it sounds. It is the skipping and sticking of your windshield wiper as it sweeps across your windscreen instead of gliding smoothly.
Typically new blades and a fresh coat of RainX or another rain repellent will result in a smooth gliding wiper blade. Some have found that worn wiper blades will chatter more easily than without the coating.
How to apply RainX and other water repellent coatings
Each coating will have unique steps for application and you should obviously follow the instructions on the packaging. RainX is pretty simple. You simply wipe it on and wipe it off. The actual application of Gtechniq G1 is a 2-step and 2-product process. No matter the product you decide to use, you should properly prepare your windshield before you apply it.
Obviously you should clean the glass with a good glass cleaner. Our favorite product and one that is loved by many others is Stoner Invisible Glass.
The next step you should perform for the best results is to clay bar your glass to remove any embedded road grime. Unless your car or truck is brand new there will be some bits of debris that are stuck to the glass. They will be very small and difficult to see but they can create a rough surface that you can feel. The longer you’ve owned your vehicle the more road grime will be stuck to the windscreen.
I encourage you to read our article on how to clay bar a car windshield to learn about how best to get the job done.
The best rain repellent for car windshields - Gtechniq G1
As mentioned at the beginning of this article, Gtechniq G1 is our pick for the best hydrophobic windshield coating.
The facts that you need to know about G1 is that it can easily last a year before needing to be reapplied. It is a 2-product solution G1 is applied first and G2 is used to remove the excess G1. The other key fact to know is that while this product is extremely long lasting, it isn’t inexpensive. The big plus RainX has going for it is that it’s insanely cheap in comparison. My opinion is that the short life isn’t worth the savings. You’ll have to make that determination yourself.
Another RainX alternative - Aquapel
Aquapel is a good alternative to RainX that isn’t nearly as expensive as Gtechniq G1. G1 may be the best alternative based solely on performance but Aquapel is a good runner up considering the cost. Aquapel lasts approximately 6 months which is significantly longer than RainX but still significantly less than G1.
It’s more expensive than RainX but a lot less than G1. If the cost of G1 puts you off I’d highly recommend going with Aquapel instead. It’s a great compromise. G1 is still the preferred option if you don’t mind spending a bit more for the extended lifespan of another 6 to 9 months past Aquapel under typical conditions.
So, now that you know how long RainX lasts under typical conditions I would imagine you don’t want to need to apply RainX every month.
Gtechniq G1 is the ideal option for its extremel longevity at over a year under typical wear and tear. It comes at a cost though. It isn’t inexpensive.
For some people they will want a more inexpensive option that still outperforms RainX. Aquapel is the best alternative for those that demand more reasonable performance but without the expense of G1. Aquapel lasts 6 months but for significantly less.
My go-to solution is Gtechniq G1 applied annually and a new set of wipers changed out at the same time. Clean your windshield thoroughly with a clay bar and a quality glass cleaner and you should have an impressive solution that you’ll be extremely satisfied with.