I changed my brakes and had my rotors turned (Note: drilled and slotted rotors can be turned, we turned the "warp" out of one of my rears) and discovered first hand the what is referred to as Galvanic corrosion between the wheel and spacer, then again between the spacer and wheel hub (much worse on this side) as my setup on the wheel hub side has been in place for 4 years (kick myself for not taking pictures).

If you are not familiar, this is also known as dissimilar metal corrosion, and it occurs when two different metals are in contact with each other in the presence of an electrolyte. Rain and harsh weather with road salt speed up this process, but my car is in the garage for the most part and doesn't get driven in the rain. Even as we cleaned everything up with wire brushes, I was still puzzled by how advanced the corrosion was on the wheel hub side.

Go here, 38 secs in to see what's happening as the more reactive/galvanic metal acts like an anode passing electrons to the less reactive/galvanic metal acting as a cathode:


Note that this will happen in the absence spacers as well since most wheels outside of the steel stockers are aluminum alloys; 6061 and 7056 alloys are stronger, lighter and less corrosive, but they are still corrosive.

My question is, How can this be prevented or slowed way down? The spacers themselves are normally anodized and made of an aluminum alloy, but that only helps a little and doesn't prevent. Others state that they apply anti-seize to both sides of the spacer, but anti-seize is conductive. Dielectric Grease isn't conductive, so that may be an option, but the effect is not lasting as it heats up and is prone to evaporation:
I found it odd that there isn't a 5x114.3mm bolt pattern high temp non-conductive gasket available that fits both sides of the spacer/wheel.

I then found that a company named Accuride makes these gaskets for tractor trailers and calls them "wheel separators", but they make nothing for passenger cars: https://www.fleetpride.com/parts/acc...tor-plate-5901

Wondering if it makes sense to buy some high temp gasket material and build a set of these gaskets using the wheel spacer as a template?

Lesson learned, check your wheel spacers often. Note that I also found one on the rear that had small hairline surface cracks around the studs. I was reading online that this is caused by your wheel/tire place getting over zealous on the torque setting. My guy this week torqued by hand, but I need to remind the tire places to do the same.

 

There are less conductive anti seize on the market.
Tef Gel being one of them.
anti seize also acts as a barrier, so the electrolyte (water) can't get in there.

Paid to have my alignment done, was very clear I was willing to pay extra to not use an impact on the wheel lugs.
they still did it
And told me my driveway string alignment was perfect, didn't even need an alignment. Still charged me. But I digress

In Florida. WD-40 in between is enough. I also lightly spray paint any raw aluminum or steel with high temp flat black paint before assembly.
There are spray on anti corrosion products available, like Corrosion-X. Look into nautical supply places.

If there were salt on the road, I might want a non compressible gasket, but imagine a light smear of anti seize would do for most road going applications.

 

Excellent feedback.

The boating guys have always had access to advanced corrosion protection resources. I should of thought to check the marine supply stores.

Tef-Gel seems perfect: https://ultratef-gel.com/product-category/ultratef-gel/

I want to move from 15mm to 20mm (25mm is flush, but it no longer looks OEM at 25mm) all around, so I have been looking at other brands outside of H&R as they are the priciest.

Z1 is an option. Good price, but they really don't mention the exact materials used (neither does H&R).

Titan in Michigan is one vendor that people in other automotive communities seem to be happy with...Titan uses 6061-T6 aluminum (H&R doesn't state which aluminum they use, only that it's an alloy) and grade 12.9 steel for the studs.
https://www.titanwheelaccessories.co...studs-set-of-4

Another company that is interesting is Bonoss out of China: https://www.bonoss.com/product/bonos...r-infiniti-g37

I learned about these on YouTube through a couple of people that swear by them. 7075-T6 aluminum (expensive material), same 12.9 wheel studs, but also a 10 year warranty. They also include a tasteful knurled design, cooling channels and a little indent to pop them off with a screwdriver (my mechanic races off road and he said most he's seen include the indent, H&R does not). Not sure on the cooling channels as this may allow water to get trapped and corrosion to occur. It's a good looking and somewhat overengineered spacer, and just as expensive as H&R.

 

I swap spacers on every winter, so that's a unique opportunity to clean the aluminum spacers when off the car for Summer. I also use a thin layer of Permatex Anti-Seize Lubricant between the spacer and the hub, which is this goopy crap you don't want to get on your fingers. Some kind of micronized silver compound, or something like that. It's weird stuff.

Absolutely the spacer adapters and the wheels need to be mounted to torque specs. Finger tight in a star pattern, then tighter still with the torque wrench until it clicks, then one last solid ugha-ugha with the torque wrench until multiple clicks. While that might seem an overly cautious approach, I like it better than a shop tech hitting one lug nut at a time with power wrench. That scares me. Granted, I let the shop do whatever they want with the family cars, but my G is handled with kid gloves.

 

My plumber uses that Permatex Anti-Seize Lubricant for everything. Appears to prevent galvanic corrosion as well.

Swapping out winter wheels is an advantage for you guys as it forces an annual inspection of the spacers. Mine were installed at the end of 2021 (almost 4 years ago), and while I always ask Discount to check the torque when I buy new tires, they are not removing the spacer.

Remind me, which brand/size did you buy? 25mm=~1", and based on my measurements yesterday. that would be the perfect size if you want the RWD/Staggered Sport wheels to sit flush.

 

Those were 15mm adapters from B2AutoDesigns. The set of 4 was $200 back in 2014. 15mm seemed the right amount of poke so that the duckfeet are flush on a sedan lowered over an inch.

IIRC, 15mm was the minimum depth as adapters, meaning they have their own studs. Anything less thick and you're talking about using extended studs.

Those Bonoss adapters look pretty cool. If I were buying a set today, I'd give them a try.