Upgraded parts cost to car value ratio: What's your rule of thumb?

What is your cost limit for parts in relation to the value of a car? For example, $3000 daily driver, do you spring for the $400 window tint or is that too much?  Would $100 window tint be in the acceptable range? 

Say the paint on the old daily driver is looking rather sad, but you plan on driving it for a while, is a $1500 paint job (half the value of the car) too much? 

Granted, on this board, most would DIY the above, but let's say you're paying someone to do it.

When replacing parts, new shocks for example, do you buy the most expensive, somewhere in the middle or whatever RA has the cheapest? 

Personally, I'm frugal and generally go towards the cheaper alternatives based on some fuzzy math of cost of the parts vs. value of the car.  I wouldn't spend $1500 on a new set of rims and tires for a $3000 car nor would I buy a $600 set of shocks.  I'd absolutely buy a decent set of tires, say $500, but would probably lean towards the lower end for shocks.  Maybe a step or two above the cheapest.  The question came up talking to the wife about her new (to us) daily.  She wants the windows tinted.  Local shop charges ~$400.  While it would be really nice and help her sensitive eyes, I just can't justify spending 10% of the cost of the car on tint and will try to do it myself with "less than professional" results.

Of course, cost doesn't apply to things like a $1500 Miata autocross car where a $1500 set of super light rims and race tires would make a difference in lap times.  Or an acr Neon that's been your halo car and you happened to score a set of original Koni's.

-Rob

I try to decide on how I am going to use the vehicle and if I *really* want to do the same job twice (which can happen over longer ownership regardless).

With my Colorado, I bought it knowing the struts and shocks were going to be needed soon, and being a regular cab, 2wd, I wanted it to sit a bit lower because I wanted it to have some personality as an appliance, so I spent some decent money on a Belltech 2/3 drop kit (eBay) and KYB struts and shocks (RA) because I didn't want to have to do the job again for a few years if I could avoid it, and heard good things about Belltech quality and have used KYB before. 

Same truck got a used ($90) OEM AM/FM/CD player to swap out the AM/FM radio it had because I couldn't justify spending large money on an aftermarket deck, wiring harness and dash kit and an OEM radio does everything it needs to do for music (for me). 

As for tinting, if it's something you are certain you can do for cheaper, I'd do it at home. If it's something that may take an attempt or two to get it right, it may be cheaper in the long run to get the local shop to do it once and be done.

IMHO purchase price of the vehicle is irrelevant to the question of how much to spend on parts.  What's important to the value of parts is how much I like the vehicle, what my goals are for it, and how long I plan to keep it. 

No correlation for me. I've been that guy that put $3k wheels on my $1k e30. Aside from my trans am, I think every one of my cars has a part on it that at least equaled purchase price...

Not an issue for me.

I put 10k into a maybe 25k car this year. The benefits outweigh the concern I guess. The car is going to be about perfect.

codrus (Forum Supporter) said:

IMHO purchase price of the vehicle is irrelevant to the question of how much to spend on parts.  What's important to the value of parts is how much I like the vehicle, what my goals are for it, and how long I plan to keep it. 

 

 

I agree with this. Wasn't there a thread on the actual cost about keeping an older, paid for car running on here?

As for things like window tint, wheels, paint and so on, that's entirely up to personal preference. Everybody is going to have a different limit on this.

Right now I'm inclined to put more into an older car to make it last or make it better as getting a different replacement is so expensive.  

codrus (Forum Supporter) said:

IMHO purchase price of the vehicle is irrelevant to the question of how much to spend on parts.  What's important to the value of parts is how much I like the vehicle, what my goals are for it, and how long I plan to keep it. 

 

 

This. 

If you bought a $20k car for $3000, you did not buy a $3000 car, you saved $17k.

If you were given a car for free, would you scrap it when the fuel tank was empty because the car isn't worth adding $30 to it?

Sometimes, the low purchase price means you have more to spend on the car :) We used to have a Miata in the fleet that was a $1,000 car with $10,000 worth of parts. It was a really good $11,000 car.

Agreed on the irrelevance.  It's about whether the upgrades are worth it on their own to me, and maintenance is more about what it would cost to replace the car than what the car is worth.

I'm generally not willing to pour money into upgrading a car on death's door though, since I'm unlikely to get enough use out of it to be worth it.

Edit:  An example in my case - I think I paid about as much for a limited slip differential as I paid for my rallycross Neon.  That was an upgrade that was very much worth it.

I agree it depends on the car, what its purpose is and what the upgrade is.

I bought a built engine for my Spitfire and the cost of that engine was almost as much as I paid for the entire car. Along a similar vein, my GT6 is getting a T-9 swap that cost more than half what I paid for the car.

My Volvo 1800ES was $800 and (eventually) will get many times the purchase price dumped into it.

Conversely, part of the reason I'm abandoning my E-350 diesel camper van project is I'm having doubts about dumping what would probably be close to $30K (or more...) into a 30 year old van with 200K miles on it.  Although ironically, if I had the funds and space to do a Cummins 12V/Allison swap into the van, I probably would. But I don't and I'm not sure I ever will - so the van needs to go so I can start looking for a newer Transit 350 PSD that will cost more, but (hopefully) serve my needs better.

There are a lot of factors that go into the equation, but the general rule of thumb for me is, will I be able to get my money back? That goes for mods and car purchases. On my last car purchase I kind of ignored that because I really wanted the car. Then I got really mad at myself as I became bored of it, and knew I was probably going to lose decent money because it was in low demand. I'm not going to do that again.

In reply to Mr. Peabody :

If I used that rule of thumb, I'd never buy another car, much less mod it...  

The first consideration for me is what room there is in the budget. Not having disposable income limits choice more than anything.

In reply to Ian F (Forum Supporter) :

That rule applies to my hobby/enthusiast type cars and motorcycles and sometimes my commuters, and I can usually do it.

It would be nice to do with our long term daily drivers like Mr's P's car, but I'm just not that thrifty

My spending scale is influenced by how much rust the car has. Example...my 2003 R53 MINI has 145K on the odometer and has rust through in the usual spots around the tail lights. With current used car prices I've been thinking of getting an estimate to cut out the rust and paint the quarters. I'll bet I'm looking at a $3K job on a $3K car, a car that needs a few other details looked after, too. So I'm torn between doing it all or abandoning ship and just go pay a premium for a much lower mileage southern car. I found a 31K mile R53 for $9500, for example. If I expect to keep a car for a few more years I'll go for replacement parts that ought to last the duration of my ownership if rust isn't the primary concern.

Irrelevant. 

And I have a bad habit of selling them for what I bought them for no matter how many thousands or tens of thousands I have in them. 

This is not a business.  It's a passion and a hobby.  

In reply to Mr. Peabody :

My problem with that line of thought is by the time I am ready to sell a car, the money is gone and for various reasons I am berking done and just want the POS gone.  When I sold my E30, that was definitely the case. I had so much money plowed into trying to make it into what I wanted and it kept breaking and it felt like it was never going to end.  I drove it with fear as it felt like every time I did, something new would break.  My Cummins was a similar situation.   Both were sold at a significant monetary loss.  But at least they are not my problems anymore. 

In reply to rob_lewis :

This is your wife's car.......pay a professional. If you want to experiment do it on your own car.

My Datsun was a $270 car in 1984; its now had $9000 invested into it.

I am also cheap I buy cheap cars so I can spend money on them for upgrades. My 9K Datsun is turning the same lap imes and giving a similar driving experience as a 90K Porsche 356. 

If you're planning to keep the car and use it for a daily driver, I think money invested to make it a comfortable, enjoyable place to spend time is not money wasted. If $400 tint will improve the wife's driving experience every time she drives it, that's not money wasted.

If I buy a car that is just supposed to get me by for a short amount of time, then I spend just enough to keep the car moving. 

I'm assuming we're talking appliances and not dream cars, right?  Cuz I bought a car for $300 in 1996 and I've put over $15,000 in it to bring it back to life.

I usually go down a rabbit hole that involves flowcharts, spreadsheets, and 2 months of research... most of it on here.  My rule is that I shouldn't spend more than 50% of the best, and get at least 80% the performance.  Like instead of buying Brembo replacement cryo rotors, the PowerStop versions on Rock Auto cost 40% as much and they'll stop my DD 90% as well as the fancy name versions.  Like tires.... Michelin is the darling, but good lord they're expensive.  Names like General, Firestone, Goodyear, and Continental can usually net you 90% as good a tire at 60% the cost.

Shocks I do a similar thing.  I could pay $400 for the Bilsteins or the Konis, but then KYAllroad and Hobiercr chime in and say, "heads up, you know that there is a Gabriel shock that I put on my [insert vehicle] that dynos out the same as the Konis for half the price."  Or with something like a battery, someone might chime in with "I work for Interstate batteries and we make a black-top version of our battery for Auto Zone and they sell it as a Duralast."

It's also mostly dependent on how it's being used.  My DD right now is a van.  I want whatever part I buy to last a long time, not cripple the ride or the weight capacity, and not be inadequate for the work I'm going to ask it to do. Water pump?  Get the good one.  Dash switch?  $2 at the junkyard.  power window motor?  Cheapest one on RA.  Tires?  One step below Michelin. If it were a challenge racer, I'd weigh the benefits.  Shocks?  I'll spend a couple bucks more and sell the passenger seat so I can be more competetive.  My 94 pickup truck?  I tend to put the cheapest crap on it possible.  When I was re-doing the intake manifold gaskets on that truck at the beginning of the pandemic, I was having trouble finding the upper/lower plenum gasket.  I found one that was stoopid expensive, so I went and bought a sheet of generic gasket material and cut out my own.  I'm sometimes that cheap.

I thought I did that with my 914.  $1500 car, I spent $500 on five immaculate four lug Fuchs and the requisite lug bolts.

Turns out all of it was ridiculously under priced.  Thanks Jim

In reply to Curtis73 (Forum Supporter) :

All good, but for some things, I'd rather spend the extra money and get OE.

I have seen sooooo many aftermarket halfshafts shudder under acceleration that shelling out for OE looks like a good option.  And sometimes OE is as cheap or cheaper: a Ford halfshaft for a '13 Focus was half the price of aftermarket.

Struts and bushings are another place I refuse to find pennies to shave, because that stuff is annoying on a constant basis if it's wrong.  Hell, I "upgraded" to ipd's heavy duty top mounts for my Volvo, and I regret THAT.  They's obnoxiously noisy.  Shoulda went with OE.

In reply to Ian F (Forum Supporter) :

I'm pretty good at not putting myself in that situation. Not because I'm smart, because I'm cheap.