Dirty Confession

C.D.

I’m a numbers geek. I like data, statistics and spreadsheets. The stuff other people dread. The things that cause normal people to wake up drenched in sweat at night. Oh, and I also have a penchant for misleading thread titles.

I collect a lot of data about my life. Ok, some of it allows me to execute and plan data driven policy in my personal life (lulz @ corporate speak). But for the most part, I find the analysis of such data fascinating. Aside from financial data, motoring data is the big area I perform collection and analysis on. I have motoring related data from July 2009 and have recently analysed it- the motivation being rising costs and the general furore amongst motorists like me, who actually enjoy driving. Each data point was collected when I filled up my tank, so they are not uniformly distributed over time (i.e. some times I’d fill twice a week, other times once a fortnight).

Black dashed lines are linear trendlines.
Solid blue lines are actual data.

We’ll start off with the fairly basic run of the mill Petrol Price vs. Time graph. As you can, that’s a pretty steep climb. It comes as no surprise to see that greatest increases were around Jan 11 and Jan 12- budget time.





OK, so you’re saying “That’s a nice looking graph, but in reality it doesn’t tell me anything I don’t know already”. I thought the same too. We know petrol has increased and is going to increase too. But has the rate at which petrol increases changed? Are prices going up faster than they did two years? I calculated the rate of change of petrol per day, so if I filled up on the 10th of Jan at 150c and then and the 20th of Jan at 155c, the rate of change was 0.5c per day. The blue line represents actual values from the pump. The red line represents no change in price. Anything above and the price has increased, anything below and it has decreased. What is really interesting about this graph, is the trendline (dashed black line) which shows that the rate at which petrol is increasing is, well, increasing. Since the start of the year to mid-February, we’ve seen an increase of 0.18c per day versus 0.11c for the same period in 2011 and 0.062c for 2009.





That’s all well and good and makes me want to clutch my wallet and never let go. But how does this affect me and my driving? In two ways actually. The first, by drastically cutting out non-essential trips. And by non-essential I mean mostly my social life as I work in rural Ireland but my life is in Dublin. Since Dec 11 my annual mileage has gone up to 30,000 km (work related) and before Aug 10 I was in Dublin, so it was <10,000 km. I haven’t included data from either period. I went from an average of 1,200km a month to 850km between August 10 and Nov 11. The social cost? Some damn lonely weekends sitting at home. I am sure it is much the same across the county for different families.





The other big area has been separating my driving into “fun” driving that I actually enjoy and get the best out of my car and “commuting”. It’s pretty soul destroying driving around like a pensioner, but the proof is in pudding. I use 25% less fuel between the two driving styles, cutting nearly a grand off my annual fuel bill at 30k km a year. I still have my fun days out though! As you can see, I changed my car in the middle of this.





Last but not least, is the TCO (total cost of ownership) of a car. People focus a lot on petrol costs, but in reality it is a small proportion of the TCO of a car. For me it’s ~25%. The reason people focus on it is that it is the most controllable of your costs. Though I suppose you could just not pay your car tax. Here are my 2011 figures for ~13,000km:

I’ve seen a lot of people trying to estimate costs in previous threads such as “The how much does your car cost” etc. Unashamedly, my figures are the most comprehensive of any I have seen on this forum or indeed, ever. Every cent I spend is accounted for, right down to my materials for car washing and tolls. Yes depreciation is a real cost, there are no two ways about it. This is exactly how a business would cost a vehicle.*





For those of you familiar with costing, my costs per km are:





The “Total Var” cost is pretty much the marginal cost. When I take my car out, it costs me on average €0.20 for each extra km I do. So that 10km round trip to the shop actually costs ~€2. My total average cost was €0.52 per km, a little under the AA’s estimate of €0.60 for most motorists. For those of you curious about what I drive, it’s this.

I hope this post was informative. Maybe it’s a bit too much for most people, but I think such information is very interesting, thought provoking and discussion promoting. I’m curious to see what my fellow motorists think.


*The only exclusion is the opportunity cost of having capital tied up in a vehicle. Conservatively, €250 p/a.
**Fixed costs- Insurance and tax. Costs that don’t change whether I do 0 or 10,000km
Variable- Tyres, servicing (should really be a stepped semi-variable..), repairs etc. Costs that change per km driven.
*** Reducing balance method based on 30% depreciation p/a, car valued at 80% of average carzone price.

C.D.

C.D. wrote: »

..................


Last but not least, is the TCO (total cost of ownership) of a car. People focus a lot on petrol costs, but in reality it is a small proportion of the TCO of a car. For me it’s ~25%. ................

None of your graphs are showing.

For me petrol costs are 50 to 75% of the costs I reckon.

Fiona

You dont do the whole yellow black belt thing? Measuring data and reducing waste? Six Sigma i think its called?

Magown3

Depreciation is the most expensive part of owning a car I think. (EDIT: most controllable part of owning a car)

Best thing to do is buy something that's already more or less hit it's bottom value (Bangernomics) and that should, according to your figures, cut your cost by approx 33%

C.D.

mrs crilly wrote: »

You dont do the whole yellow black belt thing? Measuring data and reducing waste? Six Sigma i think its called?

Yup, have a Green Belt. Didn't think much of it, at least in the course I did the stats had been dumbed down to the point of being mere tools and not offering any real insight into the data.

Tragedy

Mileage 18,000

Fuel 4117 37.2%
Servicing 2000 18.1%
Tax 1250 11.3%
Insurance 1700 15.4%
Depreciation 2000 18.1%
TCO 11067
Cost per mile: 0.614833333


Servicing is a guesstimate, unlikely to be over €2,000 and likely to be a bit under it.

ShadowHearth

You need a girl friend man... Or a boyfriend, what ever you fancy!

C.D.

Tragedy wrote: »

Mileage 18,000

Fuel 4117 37.2%
Servicing 2000 18.1%
Tax 1250 11.3%
Insurance 1700 15.4%
Depreciation 2000 18.1%
TCO 11067
Cost per mile: 0.614833333


Servicing is a guesstimate, unlikely to be over €2,000 and likely to be a bit under it.

What car is that for? I'm guessing it's pretty nice if it's costing you €1,700 for insurance. Are the costs p/a?

Tragedy

C.D. wrote: »

What car is that for? I'm guessing it's pretty nice if it's costing you €1,700 for insurance. Are the costs p/a?

Costs are since July 2010, but insurance only covers from August 2010 to present and tax includes a periods of being off the road(August until October 2010)

First years insurance was between €1,200 and €1,300, second years was €750.

Fuel figure was based on an average of 28mpg(which has been consistent in brim to brim measurements) and assuming that the average price of fuel over that time would have been around €1.409

Northern Monkey

C.D. wrote: »

What car is that for? I'm guessing it's pretty nice if it's costing you €1,700 for insurance. Are the costs p/a?

And 2k for servicing in 18,000 miles!

Tragedy

Northern Monkey wrote: »

And 2k for servicing in 18,000 miles!

4 tyres @ €200 each, one service at €250, full set of shocks and springs (f+r) at €500 and the rest on misc bits. Would never ever buy a car with tyres larger than 18" as once you go above 17" you start getting raped by Tyre Manufacturers.

C.D.

ShadowHearth wrote: »

You need a girl friend man... Or a boyfriend, what ever you fancy!

Been there, done that. Just means I've to hide my nerdiness! I just do more of the Grrr! manly stuff when the girls are about like mucking about with tools inside the car.

naughtysmurf

Yes C.D. it was too much for me

What does it all mean in words?

C.D.

naughtysmurf wrote: »

Yes C.D. it was too much for me

What does it all mean in words?

You sound like my boss !

Petrol is expensive and is getting more expensive faster than ever before! Also, despite all of that, petrol is only 25% of what I spend on my car

Northern Monkey

Tragedy wrote: »

4 tyres @ €200 each, one service at €250, full set of shocks and springs (f+r) at €500 and the rest on misc bits. Would never ever buy a car with tyres larger than 18" as once you go above 17" you start getting raped by Tyre Manufacturers.

Ahhh. Wasn't thinking of consumables like tyres and shocks when I posted that! I thought it was something crazy that needed oil changing every 3000 miles!

MetzgerMeister

C.D. wrote: »

Been there, done that. Just means I've to hide my nerdiness! I just do more of the Grrr! manly stuff when the girls are about like mucking about with tools inside the car.

So you don't do the "manly stuff" normally and only in front of girls?

Something wrong there bud

naughtysmurf

C.D. wrote: »

You sound like my boss !

Petrol is expensive and is getting more expensive faster than ever before! Also, despite all of that, petrol is only 25% of what I spend on my car

Numerous graphs and no doubt company time when twenty seven words would have done
If I was your boss I'd fire you :P

Tallon

Finally, a thread I can read in work that looks Like I'm actually doing work and pulling statistical data

barura

That's pretty cool! I do't know what else to say!

kirving

What info did you write down? Km between fills, how much you filled by and how much it cost? Interesting data, thanks.

Fiona

C.D. wrote: »

Yup, have a Green Belt. Didn't think much of it, at least in the course I did the stats had been dumbed down to the point of being mere tools and not offering any real insight into the data.

I have the yellow belt was forced to do it by my job, detested every minute of it.

Define, Measure, Analyse, Improve, and Control - those words just make me shudder :mad::mad::mad::mad:

C.D.

Tragedy wrote: »

Fuel figure was based on an average of 28mpg(which has been consistent in brim to brim measurements) and assuming that the average price of fuel over that time would have been around €1.409

Yup, when I did my anticipated TCO when deciding what to buy I factor in a 5% increase in petrol p/a. How wrong I was! You're leaving us in anticipation- what do you drive?!

MetzgerMeister wrote: »

So you don't do the "manly stuff" normally and only in front of girls?

Something wrong there bud

Bwahaha. Rains too much otherwise I'd be out doing something on my car everyday. Fixed my rattling rain sensor today- lined all the edges of the plastic cover with bluetac (rattling against windscreen).

Tallon wrote: »

Finally, a thread I can read in work that looks Like I'm actually doing work and pulling statistical data

I'm bold, I made the thread in work and posted when I got home . Another productive day!

naughtysmurf wrote: »

Numerous graphs and no doubt company time when twenty seven words would have done
If I was your boss I'd fire you :P

Pssshh. Managers love pretty pictures! Even when they don't understand them, bless their double weave designer cotton socks.

C.D.

Kevin Irving wrote: »

What info did you write down? Km between fills, how much you filled by and how much it cost? Interesting data, thanks.

Distance, €/l and litres and my car's fuel efficiency. Interestingly enough, my car is rather optimistic and thinks it gets, on average, 1.67% better fuel efficiency than it does.

ted1

What you need to look at is the elasticity of petrol

Tragedy

Nothing special, a 2.5l multicoloured Rover.