Query, 16 June 2017: “Do you have NZ data for the comparative costs of running EVs compared to Internal Combustion Vehicles? We need it for a fleet review and consideration of whether to buy EVs. Tom”
Our reply: Our test panel has been reporting monthly ‘maintenance and repair’ costs of EVs and PHEVs in the Dashboard. It includes the costs of replacing tyres. I have downloaded the report for you (for Dima’s and Olga’s Leaf, JFL445) and attach it. You’ll see that Dima and Olga have had just two modest maintenance and repairs bills since owning their Gen 1 Leaf since July 2015.
The median and 95-percentile cost of maintenance & repairs for all EVs in the Flip the Fleet database is zero i.e over 95% of the cars incur no costs in a given month. But the average bounces around a lot because sample size is still low (e.g. two members incurred large bills in Nov 2016 to cause a spike that month). I also caution that we do not yet know how representative the sample is of all EVs in New Zealand. Therefore please treat these preliminary results with caution. The average Repairs and Maintenance cost (including tyres) per month so far is $11.40, or around $137 per year. We expect PHEVs to have higher Maintenance & Repair costs in the longer run, and this sample is for all LEV types combined.
Because of the erratic nature of the observed estimates, we have started by building an expected maintenance and repair cost of ICVs into our EV ‘Return on Investment’ formulations. The repeated claim is that EVs require a fifth of the maintenance costs of an ICV. So we have started with that assumption in the meantime until we can replace the formula with a more reliable estimate of observed EV costs as above. I generated the estimated saving from the aggregated data for Internal Combustion Vehicles (ICVs) provided by AA in their ‘Running Cost Report, 2016’. I had to apply some rule that partitioned costs between the first 5 years, using a logical assumption that costs will gradually increase throughout those 5 years that AA aggregated. So I assumed that the portion of costs was 0.1, 0.15, 0.25, 0.25 and 0.25 in years 1 to 5 respectively. Tyres were considered to wear at the same rate in EVs and PHEVs as in ICVs. Each of NZ’s main EV type were allocated to the closest of the AA vehicle size categories. The resulting estimates of the saving of EVs per month are as follows:
Maintenance and repairs per month
Most of our test panel are Leaf’s and in the first 3 years of their life, so we expect the average savings on maintenance and repairs to be around $98 per month, the equivalent of $1,180 per year. In very round terms this saving is around a third of the overall savings of EVs if maintenance and repairs and energy costs are combined assuming an average distance travelled. Note that our crude first observed average maintenance costs of EVs ($11.40 per month including tyres) is way lower than that expected using our assumption of it being a fifth of the AA costs, so it may be that EVs are even more cost effective than commonly asserted. I think you might use $100 per month saving as a conservative estimate of the Maintenance and repair costs in the meantime. We can offer better estimates in a year or so.
Please acknowledge Flip the Fleet in anything you publish/report on this (our data is crowd sourced and provided ‘By EV owners, for future EV owners’, so we figure they deserve credit for their contribution and that the latter will keep them energised to continue contributing).