I installed a gasoline engine in my Rivian

[Campmohave]

I’ve got a Champion 6500w, run about 3.6kw, came to about the same here. I did have a problem with the CO monitor doing its job, so cut it off and it can now run in tight, dangerous places like the semi covered truck bed. When in a pinch, it’s worth the extra space for sure.

On another note, I love the 650. I’m selling my Husky 350 and just going to relax on my Hodakas. I needed to slow down for my family!

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[JeremyP]

15 mpg is reasonable (other than having to listen to a generator running for hours!); our bmw i3 with the 600cc scooter engine range extender only gets about 35 mpg at 70mph running on gas, and I'm assuming that's dc going directly to the battery instead of losses from converting ac to dc.

 

[mkhuffman]

I’ve got a Champion 6500w, run about 3.6kw, came to about the same here. I did have a problem with the CO monitor doing its job, so cut it off and it can now run in tight, dangerous places like the semi covered truck bed. When in a pinch, it’s worth the extra space for sure.

On another note, I love the 650. I’m selling my Husky 350 and just going to relax on my Hodakas. I needed to slow down for my family!

I have a Champion 8000W Tri-Fuel and also had a problem with the CO sensor cutting it off. The stupid thing was sitting outside, away from the house, just like it is supposed to be. But it kept shutting off.

I put a piece of black electrical tape over the sensor and ta-da! Now it never shuts off unless it runs out of NG or propane. It even works in my living room!

The engine lasts longer if you only burn NG or propane. Gasoline messes up the carburetor and other engine parts. The vapor gas burns much more cleanly.

One day I may see how much charge I can add to my R1T with a full propane tank. That would be fun to try.

 

[SwampNut]

And this is the top reason why I hate all of this "AI" crap. I really, really hate this timeline.

sure, we’ve never expended energy and effort to move society ahead. We should stop now.

 

[CrazyOne]

So do we compare the MPG to another 2/3 ton truck with 835 HP…?

Also, fucking Microsoft (Copilot). Completely retarded answer (all the others are in a reasonable range).

Short answer: About 40–55 MPG equivalent for a full recharge from a Westinghouse iGen4500 running at 120 V × 26 A = 3.12 kW — depending on the Rivian pack size and the truck’s kWh/mi efficiency. This is an estimate based on the iGen4500’s published tank/runtime and reasonable EV efficiency assumptions.

I have notice a lot of hallucinations after the GPT 5 update. It would say that something is on the page, but neither it, not I could find the real source of it's information.

 

[VandalSibs]

sure, we’ve never expended energy and effort to move society ahead. We should stop now.

I'm all for progress!

What I'm NOT for is progress at any costs, which is what the chase for AI (and "AGI") is gonna turn into - at best. It's a waste of electricity, waste of water, and a waste of land. All that on top of destroying the average person's ability to develop critical thinking and problem solving skills, while allowing people to pretend to be "creative" when they in fact are not.

And almost all of it was done (in terms of generative "AI") by outright stealing copyrighted, creative works.

Now with all that off of my chest, I apologize for taking things off topic (kinda?).

 

[PeterSK]

SwampNut said:
Also, fucking Microsoft (Copilot). Completely retarded answer (all the others are in a reasonable range).

mkhuffman said:
It is important for us to maintain our ability to identify retarded answers provided by AI. Once we lose that ability, we are in trouble.

VSG said:
Retarded questions in, retarded answers out. We're already in trouble ...

All, please consider the language you use. Special Olympics and Best Buddies made great progress in getting people to reconsider and stop using the R word since the noughts, but in the past few years it seems anything goes, especially on social media. As a parent of a child born with Down syndrome I am very aware of this usage, and I’ve had her sisters in tears after someone used it in a class at school.

This is a thoughtful forum, not X. Thanks.

https://www.specialolympics.org/stories/impact/why-the-r-word-is-the-r-slur

 

[SwampNut]

All, please consider the language you use. Special Olympics and Best Buddies made great progress in getting people to reconsider and stop using the R word since the noughts, but in the past few years it seems anything goes, especially on social media. As a parent of a child born with Down syndrome I am very aware of this usage, and I’ve had her sisters in tears after someone used it in a class at school.

This is a thoughtful forum, not X. Thanks.

https://www.specialolympics.org/stories/impact/why-the-r-word-is-the-r-slur

Sorry about the child, truly. I'd never use it in reference to a person with actual mental challenges. But I disagree with the claims that it shouldn't be used as it was used here, and will continue.

Back to the topic, and now also including AI, here's a very good answer from a pretty special AI. (Special as in not available to the public, not "special" in the R-word way.)




Short answer:
Using reasonable real-world numbers, your setup is roughly equivalent to about 16 miles per gallon of gasoline, with a plausible range of about 15–17 mpg depending on exact truck spec, driving, and generator efficiency.

1. What we know
Generator side (Westinghouse iGen4500, gasoline):
From Westinghouse / retailer specs:
•Tank: 3.4 gal
•Runtime: 15 h at 50% load on gasoline(Norwall PowerSystems (https://norwall.com/content/norwall...n4500_specs_2_2019.pdf?utm_source=chatgpt.com))
•Rated running power: 3700 W
At 50% load:
•Electrical power out ≈ ( P = 0.5 \times 3700 ,\text{W} = 1850 ,\text{W} = 1.85 ,\text{kW} )
•Energy delivered over 15 h:
( E = 1.85 ,\text{kW} \times 15 ,\text{h} = 27.75 ,\text{kWh} )
•Fuel used: 3.4 gal
So fuel per kWh:
[
\text{gal/kWh} = \frac{3.4}{27.75} \approx 0.123 ,\text{gal/kWh}
]
Equivalently, electric energy per gallon:
[
\text{kWh/gal} \approx \frac{1}{0.123} \approx 8.1 ,\text{kWh/gal}
]
Your setting of 120 V × 26 A ≈ 3.1 kW is about 84% load, so the engine may be slightly less efficient than at 50% load, but without a full BSFC map the best we can do is use the known 50%-load efficiency and call the result an approximation.

2. Truck side (Rivian R1T, Large pack, Off-Road / AT tires)
EPA data for configurations close to “Large pack + 20-inch all-terrain” give combined energy use (including charging losses) roughly in this bandInsideEVs (https://insideevs.com/news/721219/2...nge-consumption-price/?utm_source=chatgpt.com))
•DM Large, 20" AT: about 496 Wh/mi (≈ 2.0 mi/kWh)
•QM Large, 20" AT: about 518 Wh/mi (≈ 1.9 mi/kWh)
So realistic combined efficiency for your trim is around
[
\text{mi/kWh} \approx 1.9 - 2.0
]
I will use both ends of that range.

3. Effective MPG calculation
General formula:
[
\text{MPG}_\text{effective} =
\frac{\text{miles per kWh (truck)}}{\text{gallons per kWh (generator)}}
]
Using the 50%-load fuel rate from above
[
\text{gal/kWh} \approx 0.123
]
Case A: 496 Wh/mi (2.02 mi/kWh)
[
\text{MPG} \approx \frac{2.02}{0.123} \approx 16.5 ,\text{mpg}
]
Case B: 518 Wh/mi (1.93 mi/kWh)
[
\text{MPG} \approx \frac{1.93}{0.123} \approx 15.8 ,\text{mpg}
]
So:
•Central estimate: about 16 mpg
•Reasonable band from EPA variants and load effects: roughly 15–17 mpg
If the generator is a bit less efficient at your actual ~3.1 kW load than at the rated 50% point, the real number drifts toward the low end of that range.

4. How to refine this with your own data
If you want a precise number for your setup, the cleanest method is:
1Note the truck’s miles driven on generator power only (or kWh added from that generator session).
2Measure gasoline added to the iGen4500 tank (or how much you burned, if you started and ended at known levels).
3Compute directly:
[
\text{Effective MPG} = \frac{\text{miles driven}}{\text{gallons of gas burned in the iGen4500}}
]
That will override all the assumptions above and give you the true field value for your truck, your terrain, and your generator.

 

[blturner]

Thanks for doing the work. I might go buy a generator now that I know what to expect. Then when my in-laws ask "What do you do when the power goes out?" I can answer "Go to the gas station, just like you." And then point out that gas stations are not any more reliable than the grid anyway, so having both is even more reliable.

 

[JM.]

Thanks for doing the work. I might go buy a generator now that I know what to expect. Then when my in-laws ask "What do you do when the power goes out?" I can answer "Go to the gas station, just like you." And then point out that gas stations are not any more reliable than the grid anyway, so having both is even more reliable.

This has to top the list of "stupid EV questions that gasholes ask." Gas is actually LESS reliable than electric, as we saw after the NC flood. The power never failed, but the gas was all full of mud.

 

[SwampNut]

I needed to slow down for my family!

I'd argue that it's our responsibility to teach kids to always live life well!

 

[therealcmj]

And this is the top reason why I hate all of this "AI" crap. I really, really hate this timeline.

That plus the fact that people turn off their brains and blindly believe whatever comes out of the magic box and use the words "AI says" as if it absolves them of spouting bullshit.

 

[SwampNut]

That plus the fact that people turn off their brains and blindly believe whatever comes out of the magic box and use the words "AI says" as if it absolves them of spouting bullshit.

ChatGPT says you're full of shit, your mom dresses you funny, and you smell.

Look, AI is just a fucking tool. We've been through converting from horses to cars, and everyone said all the same things then. Most anti-AI talk is exactly like anti-EV talk. All evolution comes with pain and cost.

 

[therealcmj]

ChatGPT says you're full of shit, your mom dresses you funny, and you smell.

It's not wrong

Look, AI is just a fucking tool. We've been through converting from horses to cars, and everyone said all the same things then. Most anti-AI talk is exactly like anti-EV talk. All evolution comes with pain and cost.

We're in the part of the tech cycle now where people don't understand that it's just a tool. And they are actively using it for the wrong things, getting bad information out of it, and are making important decisions based on that incorrect information. To the detriment of us all.

Once people learn the limitations and understand how to use it we'll all be better off.

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