LA to Tucson and back by REx

Monday morning I will be setting off for Tucson, Az about 500mi from my home. I plan on taking I10 to Palm Springs and then dropping down to I8 along the north side of the Salton Sea. This is a route I used to drive quite often when we had homes in both cities and is 520 to 525 miles one way depending on which odometer or GPS I used. I will be driving over on Monday and returning on Wednesday.
I plan to use Francis Jeffries' method to manage SOC: cruising at 65 on the REx then slowing to 55 to recharge before refueling and will turn the REx on at 75% since I have the DVDinmotion mod installed. I plan on running the climate control in Comfort and will spend most of the trip on ACC. I will also be bringing a couple of 2 gallon fuel cans for the wide open spaces! There is a level 2 at my destination so I will start my return with a full charge.
This was typically a 10 hr drive with a car load of wife and dogs, but I expect to do the trip in less time driving alone even with all the fuel stops due to a 1.9 gallon tank.

Sounds like fun. I look forward to hearing how it went.

Please give us a report upon your return home.

i love the salton sea area

magnificent apocalyptic desolation


take the new brawley bypass ... ive never been on it

You're going to wear out your fuel cap and door - just kidding lol

Let us know how it goes!

Idleup said:

You're going to wear out your fuel cap and door - just kidding lol

Let us know how it goes!

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You are right, 8 fill ups along the way! I arrived around 10 hours after I started with no drama. The REx purred along at an indicated 67mph all day long. I was getting about 70 miles to a tank so I stopped just over an hour after the last fill up. At 67 indicated the REx would lose SOC on the hills and gain a bit back on the flats so I slowed to 57 indicated for the last 5 miles before refueling to bring it back up. I arrived with 54.5% SOC due to a long stretch where I ran on battery to the next gas station.

I kept the climate control in Eco Pro at 76 and varied the fan to maintain my comfort level, it was as hot as 90 for a while, but was mostly in the mid-80's. One trick I did use once was to exit the car from the passenger door to keep the car from shutting off and resetting the REx Hold %, that way I was able to recover the few % I was low when I stopped since it recovered all the SOC during a stint at 62 later on.

good to know i can take a long trip if needed

After another 500 miles yesterday and over 1100 in three days, I have learned a few things about long range RExing.

If you are careful you can cruise at 77 (75 as per GPS) slowly running down the SOC and then slow to 57 for about one mile per % SOC in Eco Pro+ and the car will restore charge up to whatever SOC is in its memory from when it was initiated. Also once you shut down the climate control by switching to Eco Pro+ the a/c will blow cold for a surprisingly long time: at 87f I could drive for nearly 10 minutes before it got warm inside.

If you find yourself needing to refuel, but your SOC is below the starting point, just put the car in park and exit via the passenger door. When stopping along the way to use the 1.5gal tank in the frunk I used this trick to avoid the 5 miles at 57 to recharge. By preserving the starting SOC by not shutting off the car I was able to return to that point again later by balancing efficiency vs REx charging capacity.

Several times the REx kept running while I was stopped to refuel, something it has never done before allowing me to actually add .5% to the SOC by recycling the hold charge function resetting its initiation point a tiny bit higher. The same thing could happen on a long descent, so keep an eye on your SOC at all times.....

If you run out of gas, the REx shuts off and forgets your starting SOC, on a short trip this is no big deal, but with 500 mi and lots of hills I always stopped before the REx died so I could keep the SOC as high as possible. When I ran the REx dry on my last leg, I was 20 miles from home and had 71.5% SOC remaining allowing me to drive the last bit as a BEV. BTW, despite the Guess-o-Meter claims after filling up, I always seemed to go 70 mi before getting down to the last mile or two and stopping to refuel with the auxiliary tank in the frunk.

Awesome effort !!! Its just like a real car :shock:

Wow!

You're the ultimate Rexer

Hi,
epic ! A fellow long haul REx-er . Thanks for the heads-up.
Regards, Steven

Did you monitor the battery temperature? You were running all day when it was pretty hot, and I wonder what the i3 considers the optimum (or maximum) battery operating temperature.
(Ditto in the cold: I wonder what temperature the battery is warmed up to.)

It was not very warm, only got up to 90 and that only for a few minutes. Mostly it was mid 80's, in summer the same route is usually in the low 100's and I have driven it at 111 to 114.

Great thread, thanks for sharing all the tricks and tips.

---Bill.

WoodlandHills said:

only got up to 90 and that only for a few minutes.

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i thought you were talkin' about your speed

Now that you mention it, I am kind of kickin myself for not seeing what the actual top speed is while I was out in the middle of nowhere. I did see the mid 80's once during a pass, but that's all.

Top speed is listed as 93mph and that has the motor whizzing along at something like 11K RPM, if I remember correctly. Probably not a great idea to try to do that on a regular basis! I know it will do 83, and seemed to have a bit more left when I looked down and said, I better slow down! The i8 uses a 2-speed transmission on its (very similar) motor to keep the revs down since the top speed of that car is quite a bit higher.

How many miles per gallon would you say you managed while REX was running?

I haven't really calculated it out: I was thinking more in terms of miles per tank instead and I was getting about 60 IIRC although I may be misquoting myself.

New to the i3 and the forum. Just wondering how long it will be before someone designs a larger tank for the Rex? BlueWhiteFlagger.