SF Bay Area Hymotion Install - Freeway Commuting info

Not sure this is worthy of its own thread, but what the hey. I got my Hymotion installed in my 2008 Prius the Tuesday before Thanksgiving. The Installer was Pat's Green Garage in San Francisco. They did a seamless job and were very professional. Pat recommended upgrading the suspension as well ($1200 - new shcoks, struts, springs, and some other bits, plus they installed by BT Tech stiffening brace). I must say, the suspension upgrade was well worth the $1200 - even without the Hymotion install. The suspension feels much better than stock and handles better than I remember the Touring Model handling without the harsh aspects of the Touring suspension.

On to the Hymotion deal. I commute form Half Moon Bay to the financial district of SF (at least as long as I have a job). This is 28 miles each way along the coast and then up the peninsula. I am almost 100% at freeway speeds (low of maybe 50 and high of 75) and have 3 significant hills to climb. I start from my house at sea level (actually 29 feet above), drive along the coast, climb about 400 feet through an area along the coast known as Devil's slide (a sheer drop to the ocean on one side), then return to sea level in Pacifica, climb a 200 foot hill in Pacifica, and then climb to a 600 foot ridge in about 1 mile leaving Pacifica and entering Daly City (know as "The Top of the Hill Daly City" for you locals). This last climb is a very steep climb. From there I return mostly to sea level as I head up the peninsula and into SF. Only my last 1.2 miles are city streets (all electric).

I only have a few days a data so far (I did have a Scan Gauge installed - very cool and I now have an odometer with tenths of a mile). My parking garage is giving me special treatment at the moment and letting me plug in in their basement. Not sure if they will do this long term, but it is helpful to get good data.

As a baseline, without the Hymotion I was getting about 47 MPG on this commute. Over the summer I was at 49 and hoping to get to 50, but as the weather cooled Mileage dropped. I think 46-47 would be a pretty good estimate for a yearly average. I should note that I am not a hypermiler. I go at or above the speed limit (i.e. 70 - 75 on 280 - a 65 MPH freeway). I do use hypemiler techniques where I can, but will not pull away from a stop light in SF city traffic at a snail's pace to try to stay in all electric. I would probably be run over by a Muni bus if I drove that way here.

With the Hymotion, I am so far getting 75 MPG on this commute. I arrive at my garage with 2 bars left on the Hymotion pack and then plug in. I had one day where I did not plug in and I then got 60 MPG on the way home as the pack ran out after about 6 miles. In the city, the Hymotion is great. It allows you to pull away from a light at a reasonable pace in all electric for the entire time the pack has any charge. The pack has consistently run out at 33 miles so far. I am hoping this gets a little longer as the battery breaks in. I suspect that in warmer weather my mileage will go up to 80 or so. With the Hymotion pack, the engine is being used so little for a fair amount of time as I drive along the coast that it gets cold and cycles on to heat up. Perhaps I will try a grille block.

Anyway, for those of you with non-city / highway commutes I hope you find this useful. I should note that the Hymotion mileage calculator at their site correctly estimates my stock Prius would get about 45 MPG on my commute, but then estimates I should get 95 MPG if I can plug in at work. I do not see how this is reasonably possible, even if I drove 55 in the slow lane the whole way.

 

The Hymotion kit is $10K plus tax. It is probably the best deal out there right now for a true and tested PHEV vehicle. It has been CARB certified, crash tested, and carries a 3 year warranty (that allows covers any issues caused to the car as well). With the upgraded suspension, you would never know the pack is even there. I am not sure exactly all the parts they installed - I could look at my bill and report back. I know it was KYB shocks, which are a common Japanese OEM brand.

One other real positive of the Hymotion is that the car is much more responsive while the pack has a charge. In essence you have "turbo stealth" - the full power of the combined gas and electric engine - available at all times.

 

I hope you are right. The CARB software update is a bummer. Pat, the owner of Pat's Green Garage who did the install, must have the pre-update software on his car as he was able to go to EV mode without any ICE warmup. I have an EV button - wonder if I should try to install it?

The Scan Gauge II is a really neat tool - I may get one for my Volvo.

I hope you are right on the mileage. I did get about 77 MPG today, which is an improvement.

On the flip side, my car was only charging at work for about 5.5 hours today and was not fully charged when I left - this with 2 bars remaining this morning when I pulled into the garage.

 

Peak - I am not sure - it definitely warms up upon startup - no way around it. I am driving mostly freeway speeds, and what I have seen a few times when I come to a stop after being in low ICE mode for a while (i.e. coming down a hill) is that the computer will beep at me and the display will show "EV Mode Not Available." I presume this is because the engine is too cold. Now I have driven around my neighborhood and through SF for maybe 3 miles at a stretch in all EV mode with no ICE starting up before getting on the freeway.

 

I have an EV switch that is not installed. I will check with Pat's Garage next week to see if he would be willing to try this experiment.

 

Just an update on my commute mileage - it is indeed getting better. I got 85 MPG R/T Friday - 56 miles total, charged the car at my parking garage. I suppose it is possible that come warm weather I could get into the 90s. My evening MPG is much better than my morning MPG (it has always been this way with the Prius).

On the down side, apparently someone in the parking garage complained to the building manager about me charging. A bit ironic since SF is a "Green" city and not just 2 weeks ago they had a large green mayor's conference here and one of the major topics was providing charging infrastructure for EVs. The garage manager now will not let me charge unless I can get the blessing of the building manager. I'll give that a shot on Monday.