OBDLink Fuel Rate Accuracy

[fwunder]

Just getting back into OBDLink with my shiny new OBDLink MX+ I was using old Wifi elm327.

So have any of y'all determined the accuracy of the Fuel Rate PID - gal/hr?

When I selected my truck - 2023 - OBDLink automatically chose Intake manifold absolute pressure as fuel calculation method instead of Mass air flow rate or Direct Fuel Rate.

Any experience as to accuracy?

Thanks!

BTW, glad I am retired cuz OBDLink with enhanced add ons has to be the greatest time consumer of all time!!

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[Snakebitten]

It is addicting!
Especially on the Powerboost with the awesome electrification PIDs along with the traditional ICE PIDs.

 

[fwunder]

Yeah. With camping season coming up I'm particularly interested in monitoring the HV battery and ICE run times. Nice to be able to do that "remotely" with the MX+.

Playing ( errrr, I mean working ) with it the last couple of days I came across an anomaly I hadn't noticed before.

I was in - generator no load - mode and monitoring HV SOC manually timing ICE cutoff @ ~60 % SOC. I was in ECO mode. SOC reached ~58.4% and sat there. I thought that was odd. I waited several minutes and it just didn't move. Just on a thought I went into vehicle settings on Sync4 and toggled ECO mode off. SOC on gauge immediately moved up to ~65% and ICE shutdown. Very strange! I have read of others noting failure of ICE shutdown in generator mode. I'll have to see if I can repeat that test. Like I said, good to be retired!

Anyway, my initial dashboard concentrating on what I want to monitor from inside camper...

 

[Snakebitten]

Very cool!

Yeah, the generator mode "hangup", as you described, was discussed in great detail in one thread in the past. I don't remember where, of course, because at my age this forum can be a big historical blurr.

But it seems like I remember a draw of somewhere around 3400 watts (12-13amps) on the HV battery will hang the ICE on. That would be a combination of the generator load and the trucks own draw. The truck's HVAC system, if I remember correctly, is the biggest potential HV draw (directly) if the truck is in Park.

It's interesting though that your switching/toggling the Eco-idle mode un-hung it.

I'm convinced that with software, Ford could create a camping mode for the Powerboost and it could tweak the truck in so many good ways for the scenario. Interior lighting, double honk disable, and addressing the threshold for whatever it is that you experienced with the ICE cycling on/off.

 

[fwunder]

OK, I'm going to assume that the flow rate I see on OBDLink is reasonably accurate.

So, @ 1000 RPM I will accept ~1.2 gallons per hour. I don't want to wait week to let the truck run till empty and actually measure the amount used and couldn't find any other data. I suppose I could run a full tank for a couple of hours and then use a can to...never mind!

So it has been a cold rainy day, I got my fancy new OBDLink MX+, a couple of iPhones, some test loads, Team Viewer software so I don't have to sit in the truck and plenty of adult beverage. So let's start.

I ran all these tests twice and in reverse order. To be honest, I'm surprised how consistent the numbers were. I'm sure I'm repeating someone else's work, but I'm too lazy to search for it. Oh: 2023 XLT, 7.2 kW, all cab loads off. Starting with engine warm (makes a difference)

Generator mode on, of course.

Test one - No load ( nothing pugged in)

ICE off: ~57 minutes ICE on: ~3 minutes ~1.2A HV Battery observed

Test two - 725 Watt load

ICE off: ~18 minutes ICE on: ~3 minutes ~4A HV Battery observed

Test three - 1050 Watt load

ICE off: ~13 Minutes ICE on: ~3 minutes ~5.5A HV Battery observed

Test four - 1375 Watt load

ICE off: ~11 minutes ICE on: ~3 minutes ~6.5A HV Battery observed

OK, so like I said, I ran all of these twice with the same results. I used loads ( resistance ) I measured with an inline watt meter and I timed screen grabs to show when ICE started and stopped. So, I think it's pretty good data.

The big monkey in the wrench is, of course, the fuel flow rate I see in OBDLink and am using in the calculations. Anybody?

You guys can check my math but based on 1.2 gal/hr ~1000 RPM recharge or 0.02 gal/min and extrapolating recharge cycles per hour at different loads I come up with ~0.22 gal/kWh

I have no idea how Ford comes up with 32 hours @ 7.2kW. Too many variables. I'm just throwing out what I see and would be curious if anybody else sees what I see.

Here's Just a few of the screen grabs I was using along the way.

 

[fwunder]

Just to followup on the generator mode "hangup" thing.

After the first startup hang yesterday, it never hung the rest of the testing time - about 4 hours or so and about 12 cycles or so.

I started up this AM to do some more testing and the generator mode hung up on 58% on first run.

I tapped the accelerator and it immediately shutdown.

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