Economics of modding

[RoadTripRob]

Driving 20,000km a year with a 60 mpg car. 1 mpg fuel improvement= $15 saved/year, $75/5 years

Driving 20,000km a year with a 40 mpg car. 1 mpg fuel improvement= $35 saved/year, $175/5 years

Driving 20,000km a year with a 25 mpg car. 1 mpg fuel improvement= $87 saved/year, $435/5 years

Driving 20,000km a year with a 15 mpg car. 1 mpg fuel improvement= $258 saved/year, $1290/5 years

$1.15/L gas

If you drive a thirsty car you can save a lot, if you drive an economical car you would only save a bit. Driving habits and other free changes are good either way.

To get a financial benefit of riding a $1000 bicycle you would have to ride Roughly 10,000km before is saved you $1000/gas. Plus the maintenance for 10,000km would add $200 minimum. So You would have to ride at least 13,333km (8,300 miles) just to break even vs a 30mpg car. I have started riding more often and so far I have done about 200km commuting on my bike. By the end of summer I should have 1500km. It won’t pay for itself for a long time but it is my hobby too so it doesn’t have too. You could quite comfortably half the price and no. of km required.

A lot of us do modifications as a hobby, but if you have a 40 mpg car you have a very limited budget if you want to save money. This doesn’t account for mods that cause advanced wear on the engine/car. E.G stopping/starting car more frequently= need a new starter motor more frequently. If the starter motor costs $300 installed and you use it 5x more than normal the amount you might spend replacing it would never pay for the fuel savings you achieve.

I want to buy a scanguage 2 but my smart already gets 62mpg, the $220Cad price tag would never be worth it. $140Cad ultraguage is better but seemingly never in stock. I could get something like this for $70 cad https://www.aliexpress.com/item/Turb...08.4.11.FASVN3 It wouldn’t save me any money but it would at least pay for itself.

[Fingie]

my crapster gets 35 mpg average on a good day and a new starter is 50 bucks and it's not hard to change.

but any other mods, like thinner oil seems to not affect the life of a gearbox/ engine really that much, if you maintain oil levels and change often enough.

It'll wear out faster, for sure, but for example a well designed gearbox often outlasts the engine. And engines in general last nowadays very well.

And at higher miles, the car itself will be worn.


Maybe if you want to keep the car, you should not do any radical tests with lubricants.

warm air intake should not really do anything bad in a long run, as many cars have some type of wai system OEM, and still last





I use a 20 buck bluetooth-OBD tool to readout values from my car. I can also delete fault codes= saved money because a shop is not needed.



I don't care about my crapster, the parts to it are so cheap, so i can replace them as needed.

Pistons, rings, syncros, etc.

almost all indvidual parts for my car have prices counted in tens of bucks, not in hundreds

Russians are very stubborn with owning a car well beyond their designed life. Lotsa aftermarket.

[nemo]

Don't forget to factor in the other costs of owning a car. Purchase price and or depreciation, insurance and taxes.

[puddleglum]

Glad to see someone started a thread like this. Hopefully it gains some discussion momentum. What you drive and how much you drive definitely affects how much you can spend on mods and have them pay for themselves. It raises the question, what is a reasonable payback time for a mod? Is it a year, two, the life of the vehicle? Does a mod need to pay for itself at all or is it enough to just have bragging rights that we're getting awesome mileage. Everyone's situation is different so I don't know if there is one right answer. I haven't had this car a year but I only expect to drive it about 5000 km/yr. Any mods I do have to be really cheap if I ever want to see a return, even if the mod gains me 3-4 mpg. I see guys here doing some pretty expensive mods, engine and tranny swaps, major body work. Some of it is pretty awesome stuff and it may even pay off for them. Lots of guys here drive more in a day than I drive in a week. It certainly wouldn't for me. What or how far we mod is really subjective to our situation.
In a way, my car itself is a ecomod. It replaced my van that used three times as much fuel and was useless to me. I've been able to reduce the use of my other car that uses twice the gas by a couple hundred km a month. Finding the right vehicle for your needs, if your current one isn't, may be one of the best mods. As for biking, going out and buying a $1000 bike to save gas may not pay off quick, as you say. But, if you have a bike already, or you buy a $300 bike to save you from driving the 12 mpg gas guzzler, it's payback will be pretty quick.

[California98Civic]

Originally Posted by nemo

Don't forget to factor in the other costs of owning a car. Purchase price and or depreciation, insurance and taxes.

Yes. And for me, keeping this 1998 Civic as my daily driver since 2001 has been a MAJOR depreciation saver relative to new cars or near-new used cars. Part of keeping my civic cheap to own as it ages has been learning to do all repairs myself. I learned that by modding as well as repairing. My transmission swap cost $300 in parts, but I learned so about my drive train by doing it. So the financial benefits of modding are more complex than merely the cost/savings of a given mod because it is also mechanical training. Long ago, I learned to look at the economics in this holistic way. The key is to retain my dedication to this one car as a financial strategy.

[vskid3]

There's a million different ways to look at what's worth it and what works for you. Yes, the bike may take thousands of miles to break even, but what if you replaced a car with the bike. Insurance and registration for my car could easily pay for an entry level bike every year, which is why we just have one car. That's not even considering the health benefits of the bike. That old truck you use to haul whatever once a year may cost you more in registration fees and insurance than renting a truck from Home Depot, but maybe it's worth it to you to keep because it has sentimental value. Being worth it doesn't always mean it's the cheapest or best option, just that it's the one you like.

Here's a spreadsheet I made years ago to compare the cost of doing a mod or upgrading to a higher MPG car. The numbers make more sense if you put the lower MPG/modification cost car on top (usually the current car), but I think it works out the same either way (it'll just be negative). The green cells are the ones you change to fit your scenario.
https://docs.google.com/spreadsheets...it?usp=sharing (I think you have to save it to your Drive or computer before editing)

Here's the formulas for those who can't download it or want to make their own.

[Ecky]

I recently moved from a rural area to an urban one, and my economy tanked. However, I walk to half of the places I shop now, and rather than going through a tank (700-850 miles) every week, it's looking more like a tank every ~3 months. Given that, almost nothing I do to my car will have a positive ROI. However, it's one of my favorite hobbies and I justify my spending on it mostly by the skills I learn and the enjoyment I get.

I don't ever intend to sell my car, but one factor I consider is reversibility of mods, most of which can be pulled off and sold, and reduce the aftermarket value of the car if left in place. For example, when I splice the harness, I prefer spade connectors rather than soldering into it. When I pull a part off, it goes into a big box of spare parts. Even my headlight projector conversion is entirely reversible.

Bicycles are a bit hard to quantify, because it's more than the gas saved. A bike (vs no bike) reduces the number of cold starts and short trips in a car. It expands one's transportation options - in many cases it's faster and more convenient for me to bike, nevermind the economics. It has health benefits, and it removes another vehicle from the roads, which is of benefit to everyone from both environmental and traffic congestion perspectives. And, bicycles too have resale value.

~

Only semi-related, but one of my favorite pictures of MrMoneyMustache:

[California98Civic]

Originally Posted by Ecky

... Only semi-related, but one of my favorite pictures of MrMoneyMustache:
...

Now that is a great example of a workout replacing a sitting session while also burning less fuel. Must have been slow riding, though. Would be cool if it were possible to make the trailer axle extendable a couple feet for great stability.

[Hersbird]

$1000 bike? I don't get that. Either you ride a bike to save money or to get exercise, either way a $300 bike is the way to go. Me I'd go with a older $1000 Honda motorcycle first, then again I buy a $3000 car every 5 years, usually it's still worth $1500 or more resell, had a one time $300 license fee, costs $350/yr to insure and about that much on maintenance. So that's $1000/yr before buying gas. It gets 25 city which is where I mostly drive it which works out to .10/mile more for gas. I could certainly find something cheaper as well but I like AWD, power stuff, A/C and everyday relialibility so I pay 3x what I could up front for a Subaru.

[aardvarcus]

There are other hidden economics beyond the obvious. For example if you modify a vehicle to get better MPG by reducing the load on the engine due to aerodynamic drag, correspondingly you should also expect a bit longer life out of that engine (unless you did something bad like over blocked the engine cooling). Once you start making major modifications where you appreciably increase the range of the vehicle, you can then fill up the vehicle less often which saves you a bit of time at the pump. Especially with pickup trucks, many spend thousands of dollars on aftermarket replacement fuel tanks to increase the range of the vehicle, typically by around 50% or so. Making a vehicle burn 33% less fuel would provide the same range benefit as a 50% larger tank. Depending on your perspective, this convenience factor may be worth something to you.

I think for many though (like me) it is more of a hobby, and there aren’t many hobbies that have any positive ROI at all, most have highly negative ROI.