So I've thought about lowering my car for quite some time now. Most likely eibachs or swift spec r. My concern is my original struts already have a pretty decent amount of miles (just hit 69k). Should I bother lowering it or save up for some coils?

 

It really depends on the results you want. Cheap coilovers will cost about the same as quality springs and shocks (ie Bilstein HD with your spring of choice).

The springs + shocks will give a more comfortable ride and require less maintenance.

Cheap coilovers will require some maintenance, probably be a bit harsher, and make strange noises from time to time, but will give you more flexibility to adjust height, spring rates, and alignment.

Most people should just get new springs and shocks. If you want the flexibility, and don't mind the noise and hassle, then go for coilovers.

 

Honestly everyone I have talked to that wanted more out of their suspension that went to springs and struts wound up going to coilovers down the road. I'm a huge fan of do it once and do it right, but budget kills that theory a lot. I personally run on my Evo 8 (daily driver for 3 years) BC BR's through rain, salt, snow and sand. Minus a little bit of cleaning twice a year they clean up awesome. If you've ever been to boston you'll know the roads here are like rolling through a rock quarry and these have held up to 60k of harsh New England roads and my "drive it like a race car" mentality with my personal cars. Overall I'm amazingly happy with them, I purchased them before I started working for KT but now to this day they're one of my best selling coilover systems for people who are on a budget and don't spend much time on the track. Its great for a weekend warrior and sunday spirited driver.

Another good option would be the ISC coilovers which have been up and coming with their products, local and based out of the New England area a few of my tech and a bunch of my customers swear by their setup, price wise they're a bit cheaper but the quality is similar to BC.

Most of the strange noises I hear are from the car flexing due to the rigidity of the coilovers, on full soft the BC's are a bit bouncy but ride a bit stiffer than stock over bumps. I have full chassis underbracing on my evo so I feel everything. I have them set to 75% stiff right now with my front bumper sitting just below 3" off the ground with a do-luck style front lip. I raise it every winter and lower it every summer.

If you want to sway from coilovers the Bilsteins are a great strut choice and I love Swift springs. My buddy had them in his IX and it rode smooth and still cornered pretty good. It did have a slight bounce to it which bothered me, but coming from my setup it was expected. With that being said, install wise it might be cheaper to just do coilovers, its just the initial investment for the coilovers. Springs you'll have to pay for loading them up into the strut on top of removal, but you won't have to worry about adjustment. Its all a trade off.. and owning a evo is a never end wallet emptying process...

Sorry about the essay, its been a slow morning and I'm wired on coffee.

Edit: Most people will tell you just to do struts and springs. I'm partial to coilovers because I like the adjustability and the ability to make my ride tailored to my interests.

 

If you don't mind sacrificing ride quality, go with coilovers. Personally, after having coil overs on many of my past cars (all S13's, S14's) it sucks if it's your daily driver. For the Evo, I went with Tanabe GF-210 springs on factory shocks (120k miles) and I love it. Ride quality is still great, while having about 20-30% stiffer springs. The only problem I ran into was having to swap out the strut mounts. Examine your shocks before doing it though. My car has been extremely well taken care of and runs like it has 60k miles instead of 120k. Eventually, when I get another daily driver I will run coilovers, but until then I'm happy with springs. Hope this helps.

 

As someone who has gone the top-dollar struts and springs route in the past (other model vehicle).... you'll likely want coil overs afterward. It might be a month, it might be six months... but you'll probably want them for one reason or another. I had half the parts dumped in my lap, but still had about 900$ invested in a $1500~ set of suspension (all new OE mounts, bumpers, etc). Even at that, with the closest decent/reputable coil over set being over $2000, I still felt it was a terrible deal after driving a little while on them. You just can't beat coil overs on anything but price.


But to answer your original question regarding mileage on the stockers.... The lowering springs move the location of the shaft in the strut out of it's normal neutral location, making the valve operation outside it's normal range of travel and will cause premature wear technically. But it is done all the time and is far from a rule. I have had cars with nearly 200K on factory struts get lowering springs put on and were still fine 50k later. If the strut is going to fail it is going to fail. While the lowering spring will likely accelerate the process, if there is nothing at all wrong with the struts to begin with they will likely last a long time regardless of springs.
You are more likely to see strut mount failure than anything else.