Used 2018 Model X Getting Nervous! Should I Be?

[Dlandfan]

I am scheduled to pick up a “new to me” Model X on Saturday! I typically buy new cars, so a little nervous to buy something used.
It is a 2018 MX 100D with 23,000 miles. Looks to be in great shape … I’m excited but reading some forums and now I’m nervous! (Reading about axles having issues and screens going completely blank) LOL
Should I be worried?? I can still back out til Saturday!!

 

[Dlandfan]

Today is the day! Thank you all for responding! My wife had a dream that when we got there they were hosing down the car inside and out and it was all soaked! You know with those falcon wing doors wide open you can just shoot right through! Lol. Hopefully that will not be the case and the transaction will go smoothly! We are looking forward to learning about all the bells and whistles and how to charge successfully at home. I’m hoping that the plug we use for the RV will be sufficient and charge it overnight. I so appreciate you all!

 

[EbS-P]

Today is the day! Thank you all for responding! My wife had a dream that when we got there they were hosing down the car inside and out and it was all soaked! You know with those falcon wing doors wide open you can just shoot right through! Lol. Hopefully that will not be the case and the transaction will go smoothly! We are looking forward to learning about all the bells and whistles and how to charge successfully at home. I’m hoping that the plug we use for the RV will be sufficient and charge it overnight. I so appreciate you all!

What’s the rv plug? 50 amp 120 V? 120v charging efficiency is less than 240, so I’ve read.

 

[Bigriver]

That is a big deal, so check to see if it is MCU1 or MCU2.

Thank you ! Is that the infotainment upgrade? It does have that

No…it is actually the computer for the autopilot and entertainment.

Yes, it actually is. The MCU2 upgrade is called the “infotainment” update by Tesla.

Infotainment Upgrade | Tesla Support

Upgrade your Infotainment system to access new features, and for a more advanced and smoother user experience.

www.tesla.com

@Dlandfan, please do check back in telling us how it goes. I don’t think you’ve told us who you were buying it through. But as you mention that you had gotten to see it and test drive it, I’m thinking it’s not Tesla. Never heard of them allowing that, for used or new vehicles.

 

[Hoosierdaddi]

Today is the day! Thank you all for responding! My wife had a dream that when we got there they were hosing down the car inside and out and it was all soaked! You know with those falcon wing doors wide open you can just shoot right through! Lol. Hopefully that will not be the case and the transaction will go smoothly! We are looking forward to learning about all the bells and whistles and how to charge successfully at home. I’m hoping that the plug we use for the RV will be sufficient and charge it overnight. I so appreciate you all!

Yes you just need to buy the 30 amp adapter. That will def charge you overnight.

 

[DCGOO]

Thank you! Speaking of charging, we have a 30 amp plug that we use at home for our RV (we plug it in on occasionally at home) will that work for charging?

It will work, but very slowly. 30 amp RV outlets are only 120V, thus only good for a few miles per day. a 50 amp RV outlet is 240V and much faster.

 

[EbS-P]

It will work, but very slowly. 30 amp RV outlets are only 120V, thus only good for a few miles per day. a 50 amp RV outlet is 240V and much faster.

I will quantify a few. Call it 80 miles if you can charge 10 hours a day. Swap it to a hardwired (I say hardwired because they need 2 + ground conductors and you don’t have to pull anymore wire) wall charger on 240v and you double it. All you need to do is have/make one extra slot in your breaker panel.

 

[Bigriver]

Thank you! Speaking of charging, we have a 30 amp plug that we use at home for our RV (we plug it in on occasionally at home) will that work for charging?

The Tesla shop has helpful information on different plug options and rate of charge.

Note that these adapters are for the Gen 2 mobile charger. My 2017 MX came with Gen 1 that uses different adapters (not as long), which Tesla currently sells only a few adapter options.

 

[KentuckyX]

Today is the day! Thank you all for responding! My wife had a dream that when we got there they were hosing down the car inside and out and it was all soaked! You know with those falcon wing doors wide open you can just shoot right through! Lol. Hopefully that will not be the case and the transaction will go smoothly! We are looking forward to learning about all the bells and whistles and how to charge successfully at home. I’m hoping that the plug we use for the RV will be sufficient and charge it overnight. I so appreciate you all!

So…how did it go?

 

[posity]

BigRiver did a nice chart of the Tesla adapters that have been offered but ironically NONE of those are an RV 30 AMP (called a TT-30R). On my 2018 MX, an RV 30 AMP (which is 120V) is only good for around 7 MPH charge rate which is not all that great. The max I can get from the Tesla mobile charger is around 21 MPH charge rate: that requires a 50 AMP 240V receptacle (a 14-50R or 6-50R). It just depends on how much you drive your X and how long you leave it plugged in each evening whether that 7-ish MPH charge rate will work for you.

As a new Tesla owner, it is handy to know about (and carry) a variety of the different adapters available. I've bought all the Tesla corded adapters shown above and quite a few other adapters from AC Works (so I'm never stranded due to not having the right plug). AC Works make a ton of adapters, pretty much anything you could imagine. I carry a bunch of adapters around in my frunk (both the Tesla corded adapters and some AC Works adapters that usually plug in to the Tesla 14-50 corded adapter). This is probably on the 'overboard' end of the spectrum, but was a small expense compared to the price of the X.

To use the full capability of that 30 AMP 120V receptacle, an inexpensive approach would use an adapter to convert from TT-30 to 14-50: that is the AC Works RVTT1450. Presuming your Model X comes with a mobile charger and a 14-50 Tesla adapter, you would plug the Tesla 14-50 into the AC Works 14-50R to TT-30P adapter, then plug that into your TT-30R receptacle. Then on the screen of your X, you would set the maximum charge amps to 24A (80% of 30A). You'd need to manually set the max amps to 24A because the Tesla 14-50 corded adapter sets the max amps to 32A (80% of 40A) and your car has no way to know you've installed that TT-30R adapter, so you have to 'help' your Tesla and manually set the maximum current from its default 32A (with the Tesla 14-50 corded adapter) to 24A.

Lots to learn at first. Fairly easy stuff though. Tons of different receptacles in the wild, all have different ways to adapt to them. And if you are ever adapting, you need to know that 80% rule: never charge at more than 80% of the rating of the plug (and breaker) you are using. When you are just using the Tesla corded adapters, they automatically figure out that 80% rule. But when you start adding other adapters, its just something you need to consider.

 

[Dlandfan]

No…it is actually the computer for the autopilot and entertainment. When you look at the screen on about the vehicle it should tell you what it has. I am sure someone here can post a picture of an x showing you what to look for. Do a little reading this evening here on the MCU differences, as it could matter to you…or not. Definitely enjoy what you get…once you get it, and ignore the “newer has…” you can drive yourself crazy with that.

Ok we have the car and it is MCU2

 

[Dlandfan]

So…how did it go?

It went good! We got the car on Saturday and yesterday we took it for a drive for a couple hours. Everything seems to be working well. The kids had fun with the caraoke! I was a little disappointed that the dealership didn’t really “make it shine” for pick up (like it didn’t even look like it really got washed!) But it still looked to be in great shape. Just a couple of “used car” touches.

 

[Dlandfan]

BigRiver did a nice chart of the Tesla adapters that have been offered but ironically NONE of those are an RV 30 AMP (called a TT-30R). On my 2018 MX, an RV 30 AMP (which is 120V) is only good for around 7 MPH charge rate which is not all that great. The max I can get from the Tesla mobile charger is around 21 MPH charge rate: that requires a 50 AMP 240V receptacle (a 14-50R or 6-50R). It just depends on how much you drive your X and how long you leave it plugged in each evening whether that 7-ish MPH charge rate will work for you.

As a new Tesla owner, it is handy to know about (and carry) a variety of the different adapters available. I've bought all the Tesla corded adapters shown above and quite a few other adapters from AC Works (so I'm never stranded due to not having the right plug). AC Works make a ton of adapters, pretty much anything you could imagine. I carry a bunch of adapters around in my frunk (both the Tesla corded adapters and some AC Works adapters that usually plug in to the Tesla 14-50 corded adapter). This is probably on the 'overboard' end of the spectrum, but was a small expense compared to the price of the X.

To use the full capability of that 30 AMP 120V receptacle, an inexpensive approach would use an adapter to convert from TT-30 to 14-50: that is the AC Works RVTT1450. Presuming your Model X comes with a mobile charger and a 14-50 Tesla adapter, you would plug the Tesla 14-50 into the AC Works 14-50R to TT-30P adapter, then plug that into your TT-30R receptacle. Then on the screen of your X, you would set the maximum charge amps to 24A (80% of 30A). You'd need to manually set the max amps to 24A because the Tesla 14-50 corded adapter sets the max amps to 32A (80% of 40A) and your car has no way to know you've installed that TT-30R adapter, so you have to 'help' your Tesla and manually set the maximum current from its default 32A (with the Tesla 14-50 corded adapter) to 24A.

Lots to learn at first. Fairly easy stuff though. Tons of different receptacles in the wild, all have different ways to adapt to them. And if you are ever adapting, you need to know that 80% rule: never charge at more than 80% of the rating of the plug (and breaker) you are using. When you are just using the Tesla corded adapters, they automatically figure out that 80% rule. But when you start adding other adapters, its just something you need to consider.

Thank you! So we have a 30 and a 50 amp plug - and we have the 50 plug adapter. We have the mobile kit. When I plugged it in on the app it said 32A - so does that mean that I should never charge more than 80%? Also the the cord is about 3 feet too short (if I am in the garage) so I bought an “extension” - it said it was a tesla extension cable … are those ok to use?

 

[Harvey Danger]

32A is great. You can charge more than 80%. You can use an extension. It's all good for now.

 

[posity]

Thank you! So we have a 30 and a 50 amp plug - and we have the 50 plug adapter. We have the mobile kit. When I plugged it in on the app it said 32A - so does that mean that I should never charge more than 80%? Also the the cord is about 3 feet too short (if I am in the garage) so I bought an “extension” - it said it was a tesla extension cable … are those ok to use?

As soon as you use any adapters (other than the Tesla corded adapters that plug into your mobile charger base), yes you need to make sure you don't exceed that 80% rule for the breaker on that circuit. For example, for your 30A RV receptacle, it presumably has a single pole (120V) 30A breaker in your electrical panel (I always open the panel and check the actual breaker size feeding the receptacle). So if you've installed an adapter from the Tesla 14-50 cord to use your TT-30 receptacle, you do need to set the Tesla charge current to 80% of 30A which is 24A (set it to 24A from the screen on your Tesla).

You will certainly get people here that are adamant you should not use an extension cord. Extension cords are, by electrical code, meant to be used for temporary purposes and that is certainly good practice. I would not consider using a cord for a 'permanent' application like you are describing, but I definitely do carry a 14-50 25 foot 6 awg extension cord in my frunk for temporary use on the road. If you are limited to just the TT-30 at your house, I would consider hiring an electrician to install a 14-50R receptacle at your home in a location that does not require any extension cords: then you'll get the full 21 MPH that is possible using your mobile charger (instead of the 7 MPH using the TT-30).

And congrats on the X. It is amazing. We are 4 years into owning it and have been thrilled. Still waiting for new versions of the autopilot software that hopefully will achieve true full self driving someday. Owning a Tesla is always a bit of looking forward to the future as things slowly get better and better with each software release. Welcome to the future!

 

[Harvey Danger]

Definitely a better answer.

 

[Dlandfan]

As soon as you use any adapters (other than the Tesla corded adapters that plug into your mobile charger base), yes you need to make sure you don't exceed that 80% rule for the breaker on that circuit. For example, for your 30A RV receptacle, it presumably has a single pole (120V) 30A breaker in your electrical panel (I always open the panel and check the actual breaker size feeding the receptacle). So if you've installed an adapter from the Tesla 14-50 cord to use your TT-30 receptacle, you do need to set the Tesla charge current to 80% of 30A which is 24A (set it to 24A from the screen on your Tesla).

You will certainly get people here that are adamant you should not use an extension cord. Extension cords are, by electrical code, meant to be used for temporary purposes and that is certainly good practice. I would not consider using a cord for a 'permanent' application like you are describing, but I definitely do carry a 14-50 25 foot 6 awg extension cord in my frunk for temporary use on the road. If you are limited to just the TT-30 at your house, I would consider hiring an electrician to install a 14-50R receptacle at your home in a location that does not require any extension cords: then you'll get the full 21 MPH that is possible using your mobile charger (instead of the 7 MPH using the TT-30).

And congrats on the X. It is amazing. We are 4 years into owning it and have been thrilled. Still waiting for new versions of the autopilot software that hopefully will achieve true full self driving someday. Owning a Tesla is always a bit of looking forward to the future as things slowly get better and better with each software release. Welcome to the future!

Thank you for your insight!

 

[Dlandfan]

I am using the tesla corded adapter and plugging into a 50 amp plug. (We have a 30 and a 50)
I used an extension cord last night (big thick thing!) but I’ll call an electrician to see if I can have the plug moved to inside the garage
thank you again ALL for your words. So far I am loving our Model X!

 

[EbS-P]

I am using the tesla corded adapter and plugging into a 50 amp plug. (We have a 30 and a 50)
I used an extension cord last night (big thick thing!) but I’ll call an electrician to see if I can have the plug moved to inside the garage
thank you again ALL for your words. So far I am loving our Model X!

Just ask what he would charge to install a wall charger connected to 240 volts too. I really like mine.