Repair-It

Ok I threw this together.

I just started with some basic requirements and put my own weights on them. 3 of the 5 requirements require normalization which I take care of, given a reasonable best/worst range (the other worksheet). Don't type in the gray fields.

For example, power/weight. I figured a high water mark for this purchase is about 400 hp to 3850 lbs (which translates to CTS-V1 performance). And the low water mark around be around 100 hp and 3200 lbs (Ranger with a passenger). The actual value of the vehicle under evaluation scores from 0-10 depending on where it falls in this established range.

I did the same thing for EPA combined fuel economy (2008+ standards) and interior volume.

You want the values to be somewhat realistic bounds or the resulting score won't be sensitive enough to these values (i.e. if we looked from lawn mower to top fuel dragster in power/weight, all of these vehicles would rate almost the same and it would make no difference). So take a look at those.

Then you end up with a raw score and a weighted score.

The idea is, you can tweak around with the weights to properly reflect preferences. Try to put some dynamic range in there unless she really doesn't care about one more than another. And you can add requirements as necessary. If they are quantitative they will need to be normalized from 0-10.

What I did not factor in was pricing or availability. In other words, if you guys fill this out, and you find a winner, it is up to you to find an example that exists and is affordable. I assume you wouldn't enter a vehicle in the list if it was a totally impossible proposition.

Besides, price and availability are variables. The things captured in this matrix are, hopefully, constants. The good news is, if preferences shift and one thing becomes more or less important, that can be changed and all vehicle scores would be recalculated, which is cool.

Here is a OneDrive link to the file for group editing (use this, not the attachment): https://1drv.ms/x/s!An5lt1BKvFKdqKg-nYJxkNN2ILrgRA

Where are you finding interior volume specs? I haven't found a consistent source plus most numbers I've found don't make sense (like they are quoting cargo volume for passenger cabin volume).

Source for 2000 Civic Si:
https://www.iseecars.com/car/2000-honda ... dimensions

Passenger Volume (ft³)
82.6

Good point though. We need to either stick to passenger volume or total interior volume which does include cargo space. Not sure which is more relevant - both have their merits for this exercise. I kind of like total.

http://owners.honda.com/vehicles/inform ... oupe/specs
Cargo Volume (cu. ft.): 11.9

So that would bring the total to 94.5. Let me know which you want to use and I'll correct the ones I did.

I've updated to EPA total (includes cargo) and tweaked some other stuff.

Once we get a bunch of cars in here she'll have to actually rate them according to her standards (and your interestingness rating). Also, she'll need to apply proper weights to each criteria.

Should we add reliability? Or, perhaps more relevantly, some number that represents the total cost and labor of operations and maintenance for each car. This would be a swag and maybe that isn't a good idea. It has to include the purchase price to be truly relevant.

Trying to think of other major requirements.

Have these so far:

Also use OneDrive/Excel Online for edits because my Excel 2013 did not like sharing a session with you. 2016 may be better but I don't have that. Online lets you do it though, and we all have that.

I showed her the spreadsheet. She was....annoyed that we were trying to apply logic and maths to solve a problem. The good news is I got more information about the relative importance of various requirements. I adjusted the requirement weights to reflect.

For: Car and Driver has an Observed/As Tested, which I personally take more stock in than EPA Highway/City/Combined.

This usually is more accurate to real life, especially with turbo EPA numbers.

Right except most of (all of?) the cars predate that I think.

My initial thought is "size" should be based on passenger compartment volume as that is where the perceived "size" of the car comes from. Hatchbacks complicate this, though as that is all kind of one space.

Because of that, I've convinced myself that "size" should be passenger car + storage compartment (trunk). Pickup beds don't count. Also, she doesn't want that.