Category Archives: Cars

Favorite i3 coding change – 9 L (2.4 US gal) fuel tank

One of the things I love about our i3 is the ability to code it. BMW built in tons of options that can be changed to fine tune this state of the art machine to your liking. We, software engineers, love tinkering with stuff.

One of the things I hate about our i3 is how BMW decided to code it for north american market. It is common knowledge by now that several decisions has been made to please CARB and earn zero emission credits. It is suspected (although nobody confirmed ) that to fully comply with CARBs requirements BMW needed to make sure that the car’s gasoline range is lower than it’s range when it’s powered by electricity alone. To accomplish that they lowered tank’s capacity (from 2.4 US gal to 1.9 US gal). We, software engineers, hate when accountants win.

We, engineers, on the other hand, instead of complaining, try to design and develop solution. First question was ‘how did they lower the capacity’?  Natural answer would be ‘different tank’, but further examination revealed that both EU and NA built i3s share exactly the same part number for fuel tank. So maybe they have inserted something in the tank to lower the capacity? But parts diagrams show zero differences, no bigger fuel pump, no additional plastic fillers.

Hey, how about software solution? What if the engine was being turned off despite some fuel still being in the tank?

Few minutes spent on browsing coding options reveal that there are two options with very, very suggestive names:

Screen Shot 2015-01-16 at 8.53.31 PM

The options that need to be changed are:

3005 Tank, 58

TNK_LITER_RECHTS -> mcv_rex_liter_kl_rechts (from mcv_rex_liter_kl_rechts_us)

TNK_OHM_RECHTS -> mcv_rex_ohm_kl_rechts (from mcv_rex_ohm_kl_rechts_us)

After quick coding, the display started showing about 20 more miles of available range:


 Later not so quick trip to burn all fuel that was left in the tank and here is the result:



This change is by far my most favorite one, topping easily ability to turn on hold mode.


Wheeling on Vancouver Island

Last weekend I had a chance to try some back roads on Vancouver Island. Have to say it wasn’t that bad :-)

Recovery gear

I probably should have done it before I went to Hannibal Rocks :-) Better late than never – the winch is finally on. I went with an Atlas 9500lbs winch which being quite inexpensive still has some nice features like series would motor or wireless remote.

The whole idea was to mount the winch securely and yet keep as much of stock bumper I could.


I had some problems how to accommodate universal mounting plate.


I even considered getting rid of it and fabricating something else in it’s place.


But finally I did it and it doesn’t look that bad. I also gained nice mounting point for fog/driving lights!

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First serious off-road

On Saturday I did my first serious off-road. I went to Hannibal Rocks off-road park to test my new 3″ lift I put on earlier last week. Results? I am very disappointed. I mean the lift, the whole suspension performed very well. Just my tires weren’t able to keep up with it and I got stuck two times in fairly easy (you would say) terrain.

First it was step climb. Here is the picture before:


It starts just after this mud puddle. Normally there would be no problem in going up, but my tires got filled up with mud in the puddle and they became very slick. The results?


The car went not the way I wanted it to, but slipped with it’s rear tires right into ruts pulling whole car towards the tree.


Although it doesn’t look that bad there were moments I was closer than inch from this tree. So after 3 tries I decided to back up and try another route.

Then there was muddy trail in which I just couldn’t move anymore – I got high centered – all wheels were spinning with no move at all.


Conclusions? I desperately need to buy new tires.

CB antenna mount in Grand Cherokee

Ever thought about some nice looking CB antenna mount for your Jeep ZJ? Instead of fabricating some brackets, mounts etc. go to any website selling Firestick’s products and pick up the MK204R kit. I picked up mine at Walcott CB for less than $30 and considering there is cable in the kit looks like quite cheap thing.

Now to the mounting part. I decided to put mine around rear left tail lamp. The thing is that I wanted it to be as less obstructive for tailgate and lights as it’s possible. Here is a picture how I manage to achieve that goal:



I used 4 self taping screws to securely bolt it to the body. Also the rotating part of the mount was bolted upside down – it will allow to put some heavy duty spring and quick mount and it still won’t be looking like R/C model with 5ft antenna I’m going to install.

Here you can see how I routed the cable


I used existing hole in the body, so I limited amount of drilling to zero.

Another nice thing is that tail lamp if firmly fitting in it’s place now holding the mount in it’s place and keeping it from swinging around on heavy wind.

Final efect



with 5 ft stick went over my best expectations. Now my Grand Cherokee looks clean and nice, almost like factory equipped with this.

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