Grounding Cylinder Head Test Results (2024 CX-5 Turbo)

[AL Cx5]

OK. I've finished installing two new ground wires on my 25 non-turbo CX-5. One 24-inch 4-gauge to replace the factory cylinder head ground wire on the passenger side, and one 3-ft to ground the throttle body on the drivers side to the battery ground body connect point. So far absolutely zero difference in the way that the car runs, but I'm much better grounded.

I'm a bit confused why yours is not responding like mine.

Do you own and tested the ground location with a clamp on DC amp meter. This has been my tried and true method. As discussed, putting a load on the electrical system, lights, fan on high, will divert some amps through the grounds. It reads like you landed the grounds in the correct location. I gave some values in the above posts.

Clamp on meters prices have come way down. Mine serves as a multimeter, has ports for test wire/probes. It's a real handy item to have in you box.

Maybe post pictures of the locations and we can troubleshoot or confirm all is well?

What is your test method, butt dyno? I used an app on my phone that connects to a bluetooth obd2 output. I ran the same test course on the same day and logged engine load. Emailed the log to myself, put the results in a spreadsheet and graph the results. I saw a definite increase in efficacy. It was a commitment on my part but easy to do. Carried a 10 mm wrench and connected and disconnected the ground at the car.

My butt dyno cannot detect the increase because the CX 5 Turbo has so much low end torque it's hard to feel. A NA would be detectable. I could detect better shifts after grounding the transmission.

All of this is subtle. We are not adding 10 more pounds of boost or changing camshafts. It's real but subtle.

Glad you gave it a try!

 

[jadmt]

I'm a bit confused why yours is not responding like mine.

Do you own and tested the ground location with a clamp on DC amp meter. This has been my tried and true method. As discussed, putting a load on the electrical system, lights, fan on high, will divert some amps through the grounds. It reads like you landed the grounds in the correct location. I gave some values in the above posts.

Clamp on meters prices have come way down. Mine serves as a multimeter, has ports for test wire/probes. It's a real handy item to have in you box.

Maybe post pictures of the locations and we can troubleshoot or confirm all is well?

What is your test method, butt dyno? I used an app on my phone that connects to a bluetooth obd2 output. I ran the same test course on the same day and logged engine load. Emailed the log to myself, put the results in a spreadsheet and graph the results. I saw a definite increase in efficacy. It was a commitment on my part but easy to do. Carried a 10 mm wrench and connected and disconnected the ground at the car.

My butt dyno cannot detect the increase because the CX 5 Turbo has so much low end torque it's hard to feel. A NA would be detectable. I could detect better shifts after grounding the transmission.

All of this is subtle. We are not adding 10 more pounds of boost or changing camshafts. It's real but subtle.

Glad you gave it a try!

For most the butt dyno is what matters most. Not like cx5 drivers are racing for pink slips. . Im in 2000 miles into a 3000 road trip and have been running only non ethanol 91 octane and have gotten the worst mpg i have gotten in the last 44000 miles.

 

[N7turbo]

For most the butt dyno is what matters most

The butt dyno here is no different than the audiofoolery of swapping cables to your speakers and imagining improvements (note how the sound never gets worse after spending $$$ on cables )

 

[SparkYellow]

Quick question, to test for parasitic draw, must I disconnect every accessory including the OBD dongle and keep the key fob 10 ft away? I struggled for 30 minutes and couldn't get a reading after trying every reasonable configuration. The multimeter flashed a number once, when a car passed by, but I couldn't get it to do it again. Need to get to the bottom of this before buying a new battery.

 

[N7turbo]

Did you mean to post here?

S

Thread 'Battery drain'

Mar 26, 2026

2016 CX5 GT
Having a problem with the battery draining after sitting a week.
It starts, but struggles.
I’m retired, and not driving often.
Parked in an apartment building lot, can’t do a battery tender/maintainer.

The battery is brand new, and rated at 640 cold cranking amps.
Shop checked charging system, starter, and for parasitic draw.
Everything looked fine.
I trust the shop is competent , they do fleet maintenance for a bunch of customers.

I took the car out for 1-1/2 hours of highway driving.
Checked the battery at 12.7 volts.
Let it sit 4 days, voltage dropped to 12.35 volts.
I...

• Squanchy2
• parasitic draw mystery
• Replies: 13
• Forum: CX-5 Ownership & Lifestyle

 

[SparkYellow]

No. More folks here are familiar with the multimeter like how I am familiar with chopsticks.

 

[N7turbo]

I think you should disconnect everything and only add back 1 thing at a time. I don't think the key matters, though.

See here for how to connect everything: Battery drain due to ventilated seats (2019-2022 CX-5)

 

[SparkYellow]

I think you should disconnect everything and only add back 1 thing at a time. I don't think the key matters, though.

See here for how to connect everything: Battery drain due to ventilated seats (2019-2022 CX-5)

Thank you I will try again. Still need a new battery though. Soon after the maintainer was disconnected, the level fell to 12.0 (from 13.6) in less than a minute. I haven't had good luck with batteries after the OG died.

 

[Nevada CX5]

Is the transmission more responsive and smoother shifting after added wires? Maybe.

 

[SparkYellow]

...

I think he did join us on the journey. He was first to advise me not to clip onto the chassis.

AL are you ok what's going on?

 

[AL Cx5]

I think he did join us on the journey. He was first to advise me not to clip onto the chassis.

AL are you ok what's going on?

I'm frustrated with folks who make judgmental comments and have not done an A to B comparison.

The moderators seem to ignore this behavior and make it acceptable.

I moderate two racing FB groups. We don't allow comments like Nevada or mine. The racing community knows this and takes their BS behavior to other FB groups...

If the moderators allow Nevada's comment, then I responded accordingly.

Thanks for asking and I've remove my comment.

 

[SparkYellow]

I thought he was really asking. Somewhere somehow there was a post or video saying that grounding to the transmission made a difference.

I get the level of frustration tho. I am currently all the way up to my forehead in car troubles.

 

[AL Cx5]

I thought he was really asking. Somewhere somehow there was a post or video saying that grounding to the transmission made a difference.

I get the level of frustration tho. I am currently all the way up to my forehead in car troubles.

I see that you are in the weeds with car issues. Take it one item at a time. I was surprised to see your CEL code list! WOW I hope that's a one time glitch.

I'm a bit on edge with grounding comments from previous forum experience and some folks here. I posted this info to pass on the knowledge and not defend what is working.

I've grounded many electronic transmissions. They respond with quicker, smoother shifts. It's not huge but if one is tuned in, they notice.

My other vehicle, big and LOW tech, even responded with trans grounding. Fellow vintage truck guys drive my truck are like wow, this is like a hot rod compared to mine. Grounds are part of the package. Big and dumb gets up to 30 MPG when driven consciously over 18 MPG from the showroom.

Good Luck!

 

[sm1ke]

The moderators seem to ignore this behavior and make it acceptable.

The comment was made at 7:51pm (local time) last night. You posted this comment at 10:19pm (and reported it at 10:21pm). It was not ignored, we simply had not seen it in the 2.5 hours since it had been posted. Additionally, moderators are not bots who are "working" 24/7. We are real people with real-world obligations.

I personally do not find the reported comment judgmental or negative. People are allowed to express their opinions and voice their doubt or question results within reason. Maybe you read the comment in a different way because you're defensive about this mod.

Many of us appreciate the testing methodologies, research, and feedback you have provided in the past. I encourage you to continue posting, but I suggest that going forward, you ignore naysayers and what you might call "keyboard warriors". Engaging them adds nothing valuable or constructive to the conversation. Report the comment if you think it breaks forum rules and give the moderators time to address it.

 

[jadmt]

I'm frustrated with folks who make judgmental comments and have not done an A to B comparison.

The moderators seem to ignore this behavior and make it acceptable.

I moderate two racing FB groups. We don't allow comments like Nevada or mine. The racing community knows this and takes their BS behavior to other FB groups...

If the moderators allow Nevada's comment, then I responded accordingly.

Thanks for asking and I've remove my comment.

Pretty sure he was agreeing with you. Lol

 

[CrazyHippie]

I'm a bit confused why yours is not responding like mine.

Do you own and tested the ground location with a clamp on DC amp meter. This has been my tried and true method. As discussed, putting a load on the electrical system, lights, fan on high, will divert some amps through the grounds. It reads like you landed the grounds in the correct location. I gave some values in the above posts.

Clamp on meters prices have come way down. Mine serves as a multimeter, has ports for test wire/probes. It's a real handy item to have in you box.

Maybe post pictures of the locations and we can troubleshoot or confirm all is well?

What is your test method, butt dyno? I used an app on my phone that connects to a bluetooth obd2 output. I ran the same test course on the same day and logged engine load. Emailed the log to myself, put the results in a spreadsheet and graph the results. I saw a definite increase in efficacy. It was a commitment on my part but easy to do. Carried a 10 mm wrench and connected and disconnected the ground at the car.

My butt dyno cannot detect the increase because the CX 5 Turbo has so much low end torque it's hard to feel. A NA would be detectable. I could detect better shifts after grounding the transmission.

All of this is subtle. We are not adding 10 more pounds of boost or changing camshafts. It's real but subtle.

Glad you gave it a try!

Hi Al! Just for clarification, I appreciate and trust your deep study of the grounding aspect of these cars. While I haven't noticed a butt-dyno change in the behavior of my non-turbo CX-5, I do have confidence that the heavier grounding straps are a good idea. There are enough postings here of the amperage that these cables carry to understand that heavier wires can only help. No regrets here!

 

[AL Cx5]

Hi Al! Just for clarification, I appreciate and trust your deep study of the grounding aspect of these cars. While I haven't noticed a butt-dyno change in the behavior of my non-turbo CX-5, I do have confidence that the heavier grounding straps are a good idea. There are enough postings here of the amperage that these cables carry to understand that heavier wires can only help. No regrets here!

Good to hear you are not regretting the expense and effort.

Do you do hand Calculated fuel consumption, mpg, checks before and after?

Our Mazda calculates consumption more accurately than many others but I found it varied +- 1.5 mpg. It is even off more with an aftermarket ecu tune...

As mentioned, maybe post #1, I put grounds on our cx5 the night we brought it home. I wanted the fuel saving NOW. I put the trans ground on at about the 1 year mark.

My wife still tells the story of her new car on jack stand the first 30 days getting new suspension parts.

 

[CrazyHippie]

Good to hear you are not regretting the expense and effort.

Do you do hand Calculated fuel consumption, mpg, checks before and after?

Our Mazda calculates consumption more accurately than many others but I found it varied +- 1.5 mpg. It is even off more with an aftermarket ecu tune...

As mentioned, maybe post #1, I put grounds on our cx5 the night we brought it home. I wanted the fuel saving NOW. I put the teans ground on at about rhe 1 year mark.

My wife still tells the story of her new car on jack stand the first 30 days getting new suspension parts.

Awesome! I'll keep an eye on the fuel mileage. In the meantime, can you share the landing points and length of the trans ground wire (or did I miss that in the thread)?