How Many MPG Does A 125cc Bike Get? My Boom Vader 125.

The Boom Vader motorcycle is a Grom Clone, but it’s no Honda Grom.

The Honda Grom bike is advertised as getting 100+ miles per gallon(mpg). Does the Boom Vader get the same gas mileage? Are all Grom Clone 125 motorcycles built similarly and have the same MPG? All good Grom Clone questions, but I want to address this: So, how many MPG does a 125cc motorcycle like the Boom Vader Gen 2 get?

Gas Can I use to figure how many MPG does A 125cc bike get question.
How Much Gas Does A Boom Vader 125cc Motorcycle Eat?

How Many MPG Does A 125cc Bike Get – Answer?

Information on this post, the measured miles traveled, and total gallons of gasoline measured, were last update: 5th July 2022.

Please read further, but if you want the simple answer here it is: My Boom Vader 125 gets:

68.3 Miles Per Gallon (MPG)

My Motorcycle MPG Calculations Disclaimer:

This post is a continuous calculation as we advance with possible updates to the MPG calculations based on upgrades and riding styles. As long as my Boom Vader motorcycle has the stock 125cc engine, I will continue to update fuel efficiency information here as I gather it.

Some Of My Boom Vader 125 Motorcycle’s Information:

Engine: Stock, Grom Clone 125cc engine from the factory.

My Boom Vader Gen 2 125cc Upgrades:

Larger Front Sprocket:
Boom Vader Front Sprocket Upgrade (Went Larger for more speed)

VM22 – Mikuni Carburetor:
Boom Vader Carb Upgrade (Simple upgrade for a faster bike)

High Flow Exhaust and Muffler Upgrade :
Boom Vader Exhaust Upgrade (sounds awesome!)

Possible future Boom Vader 125 upgrades:
Boom Vader Upgrades To-Do List (My little wish list.)

Boom Vader Motorcycle pictured in-front of creek bridge.
My Boom Vader 125cc Motorcycle out for a ride.

My Boom Vader Gen 2 Motorcycle Riding Style:  

I ride my Boom Vader motorcycle mostly in-city( about 25-30 mph), but I get into the back-country(45-50mph cruising speeds).  

City riding is relatively flat, with a couple of hills here and there.

Back-country riding, I look for twisty roads and hills to have fun going back down them.

Oh, I basically try to ride full throttle and high RPM for best motorcycle response.

Now that you know that, here are the results of my Boom Vader motorcycle miles per gallon tests:

My Boom Vader 125cc gets 68.3 Miles Per Gallon.

Now feel free to continue reading on and find out if I really calculated this fuel efficiency correctly, and I look forward to your feedback.

Why Do I Care About Miles Per Gallon?

Well, with the latest fix( Boom Vader Gas Tank Repaired (Again?)! ) to my leaky motorcycle gas tank( Boom Vader Gas Tank Is Leaking From Bottom, Again!?! ), I lost my ability to see the actual level of gasoline in the gas tank. As a result, I could find myself stranded if I don’t keep an eye on the amount of gas I have left in the tank.

Rather than stopping frequently and looking into the gas tank, I’ve been using the trip odometer. I did a few tests and found I can go over 100 miles and still have fuel in my gas tank.   

A hundred miles is a good round number to remember to fill up. Just have to keep an eye on my trip odometer. So that was a good workaround for missing the fuel level gauge.

Extra Travel and Gas Info I Could Have Used.

Before my Boom Vader gas tank started leaking, I was keeping track of times and mileages covered. Between fill-ups. The goal was the keep the mph low and not put much stress on the little motorcycle before the engine break-in period was completed. 

I didn’t keep that information. :/

I had direct feedback by focusing on the RPMs I subjected the new motorcycle engine to and only used the miles traveled, time engine ran, and fill-up dates as confirmation I wasn’t beating up on the machine. I lost it. 

The good news is that information would have been only valid for a completely stock engine, which wasn’t broken in, and I drove like I had training wheels on the motorcycle.

However, it was information lost for this little motorcycle. So all info for this motorcycle took place after I started doing gas tank repairs about 500 miles into the little Boom Vader’s life.

OK, I Have Miles And Gallons of Information; What Next?

Yes. I figured other Boom Vader motorcycle owners or future Boom Vader owners wonder how much it would cost to operate their little Grom Clone motorcycle. 

With this information, maybe they can figure out if a Grom Clone motorcycle is a worthy commuting vehicle compared to another car or another motorcycle.  

With the cost of gasoline today, a Boom Vader 125 motorcycle might make for a superb in-city commuting vehicle. Even if you can’t do highway speeds safely on the Boom Vader(for right now, my upgrades: Boom Vader (Grom Clone) 17t Front Sprocket Upgrade , Boom Vader Carb Upgrade (Grom Clone 125cc Motorcycle) & Basic Boom Vader Aftermarket Exhaust Mod have woken up the little 125cc motorcycle), saving a few dollars on gasoline and only losing a few minutes riding on the back-roads might be worth it.

If my commute wasn’t far and wasn’t so dependent on highway travel, I might consider commuting to work on my little Boom Vader. I would show up to work with a smile on my face. 😀

My MPG Calculations Process.

I started with a full tank(Regular gas) and collected information on how much gasoline I added to return my motorcycle tank back to full. While recording miles traveled between gas tank fill-ups.

I have at least eight travel events(gas tank fill up to fill-ups) with miles traveled and gallons used. I took photos of the odometer and pump, each time trying to fill the Boom Vader with as much gasoline it could hold.

Note, don’t completely fill up the Boom Vader to the gas tank brim. I was trying to get the most travel time out of each gas tank, and a few times, I added too much gasoline.  

The gasoline comes out of the ground cold, and once in your tank, it starts absorbing heat from the surroundings and expanding. Also, parts of the gas cap locking mechanism project into the motorcycle gas tank.  

If the gasoline level is too high, there can be spillage. Spilled gasoline will drip down onto the motorcycle engine and around the motorcycle onto the ground.

My Boom Vader Rides
With Miles Traveled and Gallons Of Gasoline Refilled:

125cc MPG Trip #1:107.4 MilesBoom Vader Gen 2 - 125cc - Gas Miles Odometer 01
 1.262 GallonsBoom Vader Gen 2 - 125cc - Gallons Gas Fill Up 01
125cc MPG Trip #2:
82.2 Miles
Boom Vader Gen 2 - 125cc - Gas Miles Odometer 02
 1.07 GallonsBoom Vader Gen 2 - 125cc - Gallons Gas Fill Up 02
125cc MPG Trip #3:69.1 MilesBoom Vader Gen 2 - 125cc - Gas Miles Odometer 03
0.776 Gallons
Boom Vader Gen 2 - 125cc - Gallons Gas Fill Up 03
125cc MPG Trip #4:
100.8 Miles
Boom Vader Gen 2 - 125cc - Gas Miles Odometer 04
Boom Vader Gen 2 - 125cc - Gallons Gas Fill Up 04
125cc MPG Trip #5:
58.8 Miles
Boom Vader Gen 2 - 125cc - Gas Miles Odometer 05
0.673 Gallons
Boom Vader Gen 2 - 125cc - Gallons Gas Fill Up 05
125cc MPG Trip #6:
75.4 Miles
Boom Vader Gen 2 - 125cc - Gas Miles Odometer 06
0.824 Gallons
Boom Vader Gen 2 - 125cc - Gallons Gas Fill Up 06
125cc MPG Trip #7:73.7 MilesBoom Vader Gen 2 - 125cc - Gas Miles Odometer 07
0.813 Gallons
Boom Vader Gen 2 - 125cc - Gallons Gas Fill Up 07
125cc MPG Trip #8:
75.1 Miles
Boom Vader Gen 2 - 125cc - Gas Miles Odometer 08
0.776 Gallons
Boom Vader Gen 2 - 125cc - Gallons Gas Fill Up 08

Totaling My Boom Vader’s Miles and Gallons Information:

With this table of information, we can calculate the total miles traveled and the total gallons of gasoline used:

Total Miles Traveled: 573.4691

Total Gallons Filled Up: 7.305

Simple math would say, take the total miles traveled and divide by the gallons of gas used to get the miles per gallon answer: 78.5 MPG.

But this would be wrong. :/

My Boom Vader Is Flawed; The Speedometer Is Wrong.

I noticed during my speed tests( Stock Boom Vader’s Top Speed Test & 17t Upgraded Front Sprocket Boom Vader Top Speed Test) that I was getting a higher indicated speed from my speedometer than I should. I compared this to a simple phone GPS app. The mismatch wasn’t a simple plus 5 miles or plus 10, and it varied based on my traveling speed.

So miles traveled per my trip odometer has to be incorrect, leading toward a wrong MPG calculation. I had to fix this or compensate for it.

FYI: Wireless GPS Motorcycle Speedometer For My Boom Vader!

Fixing My Boom Vader Speedometer, Re-calibration?

Simply put, I tried. It might be low-hanging fruit attempts, but I tried. I couldn’t figure out how to re-calibrate my Boom Vader speedometer.

A how-to YT video shows how you can hold both buttons on a Grom Clone motorcycle’s speedometer and re-calibrate it for different tire sizes. This easy speedometer fix doesn’t work for my Boom Vader.  

Wonder if it’s only for specific Grom Clone motorcycles? Who knows.

Well, I came up with an odometer solution.

My Boom Vader Speedometer Is Not Working, A Math Fix.

Well, I do the math in my head to figure my actual speed when riding my Boom Vader, but that won’t work here. So I used an app to compare my trip odometer readings with a simple phone GPS speedometer reading. Here is what I got:

Boom Vader Trip Odometer Start:

Boom Vader 125 Gen 2 Odometer Rest to zero.
My Boom Vader’s Odometer Check Start.

Boom Vader Trip Odometer End:

Boom Vader 125 Trip Odometer Ending.
Boom Vader Trip Odometer Ending.

Cellphone GPS App Start:

Cellphone GPS App Trip Odometer Start.
Cellphone GPS App Trip Odometer Start.

Cellphone GPS App End:

Cellphone GPS App Trip Odometer Ending.
Cellphone GPS App Trip Odometer Ending.

Note: I will update this information as I have more information.

My Boom Vader Trip Odometer Reading: 42.9 Miles.

My Cellphone GPS App Odometer Reading: 37.3 Miles.

From this information, we can create a correction factor to convert previously collected data from the trip odometer and correct it for actual miles traveled.  


Correction Factor(CF) = Actual Miles Traveled/Indicated Miles Traveled.

Or, in this case:

CF = 37.3 Miles/42.9 Miles

CF = 0.8695

Now we are cooking with gas.

Taking the total miles traveled from the previous Boom Vader Trip Table: 573.4691 miles

Correcting it to the actual miles by times it by the Correction factor: 0.8695

We get “actual” total miles traveled by my Boom Vader = 498.63138245 Miles

Now take the total miles traveled, divided by the total amount of gasoline used, and we can calculate the Miles Per Gallon (MPG) of the Boom Vader.

Actual MPG = 498.63138245 Miles/ 7.305 Gallons

Actual MPG = 68.258916146 Miles Per Gallon.

And with a simple round up – Ta-dah!

My Boom Vader gets 68.3 Miles Per Gallon!

Now I made this look easy, right? 😀

Hope you enjoyed reading along, and if I got this wrong, please leave a comment below. I look forward to learning, and your feedback helps.

Ride Safe, Ride Fun!

Click To See My Recommended

Boom Vader Gen 2 Upgrades

Picture of me, as a New Motorcyclist.
Just Me…Newly Licensed.

Hi I’m Tom, A New Motorcycle Rider and Blog Author.

I am a new rider(Pa Learners Permit at the end of 2020, and I received a Pa Motorcycle License in 2021 after passing a Motorcycle Safety Course).

I bought my first motorcycle, a TaoTao TBR7, at the beginning of 2021 and have been doing upgrades on that motorcycle since.

I added to my motorcycle collection by buying a Boom Vader Gen 2 in 2022, and that Grom-Clone motorcycle has been upgraded by me as well.

I continue to ride my Boom Vader Gen 2 motorcycle as well as my TaoTao TBR7 dual-sport bike.

Read more on my About Me page.

Fun Fact: I’ve only been on one group ride.

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