Robert and his team at Palmetto Auto Service got me rolling again after 3 months!!! He is professional and he knows his stuff! He corrected the mistakes of a janky mechanic and saved me tons of unnecessary money that the dealership tried to squeeze out of me! I would definitely recommend anyone go to him if you want honest and quality service.

Imagine being in the middle of driving across the country to Disney World with your wife and 10 year old daughter, not to mention being confined to wheelchair when all the sudden you realize your wheelchair ramp door wont be able to open after a piece of the panel fell off. 10 hours later in Florence, SC I google Palmetto Auto Service because Ed was the only person that would answer the phone for 2 states that late at night. Not only did he run out to the store for us after 10:00, fix it and save our vacation for us, hes just genuinely a great guy! Ill always remember Palmetto Auto. Thanks, David Harris

Robert and his team are trustworthy and reliable mechanics. In my opinion, its hard finding a mechanic that you can trust, especially as a female but his prices are fair and he does absolute excellent work. I highly recommend them to anyone in need of any type of auto repair.

Terrible customer service!!Kept my car for over a week, told me it needs a new motor which should be covered thru warranty, needed appraisal to be approved ). I was told this would take 24-48 hours..when the adjuster arrived, he told the adjuster to go home and denied the appraisal, They didnt call to inform me. After over a week of being patient with the situation and not hearing from anyone except the time I had to literally get a ride to the shop to find out what was going on, I finally talked to him to have the guy tell me some story about the appraisal man didnt want to lay on the ground so he left?? The warranty company has it documented that they denied the appraisal because he wouldnt let them put the car on the lift bc he was working on his boat. At this point after a week of getting the run around and being unable to drive to my job or go anywhere. I decided to have my car towed to a more reputable shop. Of course they would not answer the phone when I was calling all day so I told the tow truck to go remove my car and tow it elsewhere. When the tow truck arrived the owner was of course on lunch and they said I owed a bill. And would not release my car..I had to once again get a ride up there to see what was going on due to no response...on my way there the owner finally called me. I told him i was going to a new shop bc of what the warranty company said about him denying the adjuster..he immediately started yelling at me and telling me i dont know what im talking about..when I asked what the bill was for the owner started screaming at going crazy and saying he was going to charge me for storage fees for my car being on his property all week and claimed the documented report the warranty company made was not true that he denied appraisal.and proceed to yell and be totally rude and unprofessional and screamed frantically before he hung up on me..I had to call the police and go up there to get my car back..At this point Im upset and just want my car out of there, he had no reason to flip on me as I was being polite and respectful to him. When the police arrived he said he wasnt gonna charge me for storage but I had to pay 100 for a diagnostic. I felt scammed because he charged me the diagnostic fee, but when the appraisal guy came out they sent him home. The owner told me he is the owner and he only works when he wants and he was working on his boat.. and apparently he didnt have any respect for his paying customer and didnt care that i was without a car and it was effecting the business i own. When I told the guy I was going to leave a bad review he said I better have a lot of money bc he would sue me for slander but its not slander if its the documented truth.i bought my car here because they were on my warranty mechanic list.This is how they make money in this establishment so dont bring your car here or it could happen to you.

First, if you value communication like I do, this isn’t the place for you.My recent experience with palmetto auto service has been very poor. First it started off great, got a new oil cooler and a new transmission put in. After I got the car back, it was still shifting really hard, maybe even worse than when I brought it in. Was told that I needed to drive it to work it in and if it didn’t start shifting right after 1000 miles, bring it back in.So upon bringing it back in, I will admit, I had a family emergency and had to go pick it up after hours. I let them know via email that I was doing so and that I had used the spare key. Never got a response to that so I figured it was all good. Owner didn’t seem to like that when I confronted him about how long it took when I brought it back for the third time, which I’m getting to.So, the third time I dropped the car off on the 26th of May. Was told that day, “we are pretty swamped right now but, I can get to it Tuesday” (June 1st). This time I brought in for the same issues. Transmission shifting really hard from 1st to 2nd gear. Also, they exchanged some rims out for me and messed up a tire pressure sensor. Asked them to fix that as well. So I would email almost every week just for a status update, could never get one through email. Would call, Ashley would answer and take my number down, never would get a call back. To me, it would seem as if because it was a warranty, they didn’t want to touch it until they could get the money out the door first. I’m the meantime, I’m still making payments on the car. So, the warrant company in which paid for all of this through the dealership, calls me and says, “ we don’t have a claim number yet, and we are at three weeks. Have you heard anything?” So it wasn’t until I emailed them basically demanding a response with DOWCs statement about taking the car to another shop, they issued a statement about how they are working on a diagnostic. The car sat for three weeks without a diagnosis for Christ sake. Then they finally come up with a conclusion and say they can’t work on it and we are referred to a Chrysler dealership. I will be working with DOWC about all the money they have poured into this car without the car being fixed. Hopefully DOWC will take them off their list and stop referring them to their contract holders.

Great customer service, my truck was gone take a couple hrs to get fixed and because I didnt stay far, they gave me a ride home. I will be back to get my other work when need be.

I had a check engine light on I came in they diag it and got me back on the road same day in a timely fashion

Super awesome 👌 they got me where I needed to go during this pandemic thank you so much

Local mom and pop shop was willing to take my part and replace it for me. They did a outer tie rod replacement and an alignment for 240 out the door, which seemed pretty reasonable to me. The two employees seemed welcoming. My only stressor is how full their parking lot is with what I can only guess are pet projects of vehicles theyre fixing up over time. I had to park in another businesss lot and walk over.

Did a fast service to my heating and air conditioning

Robert is a great guy! Its refreshing to meet a small business owner that does what he says. I showed up without an appointment and he diagnosed the issues. He called and recommended what needed to be done and the next day my car was humming again. I will gladly send him business.

First of all, the prices cannot be beat. I shopped around at several different auto shops. Hands down Palmetto Auto has the best prices. The quality and quickness of the service was amazing. I cant express enough the awesome customer service I received. I already have someone bringing their business. They have definitely gained a faithful customer.

Great service that included informative updates, car fixed in amazing time, and great attitudes. I felt they went out their way to accommodate me and my Chevy Equinox at a valuable rate as well. I am excited to be a future customer 🤗.

Super awesome great prices and theyre the type of people that make you feel right at home and the take the time to educate you about you vehicle so you know whats going on!!!!! I can appreciate that so much

Great people. I simply had a flat and was unable to remove my spare from under my van. They accommodated me providing great customer service. Highly recommend them. Thanks again. I now have a trust worthy auto shop I can go to.

Had Robert and the guys put an Engine in my truck and a month later the transmission and transfer case had problems. (Not related to anything they did). These guys installed a new transmission and repaired the transfer case and the old girl is running Great. Just wanted to say TOP NOTCH service from all the guys. Great service and reasonable prices, cant go wrong with these guys

I was recommended by my car dealership to check out this establishment due to possible transmission failure and was thoroughly impressed. The staff was not only kind and efficient but made sure to keep me in the loop. Im sure my impatience may have been a little annoying but my car was returned in record timing and runs just as good as when I first bought it. Ive already tested the car out by driving all across the state and I have no regrets other than waiting so long to come to them!

I cant express enough how pleased I was with the service provided here. Robert was very pleasant during our wait on the car being repaired especially with such an active 7 year old lol. He made sure she was entertained while we wait. Thank you so much for your hospitality. May GOD bless you all❤

Robert is the best ! I will never go anywhere else. Fair prices & outstanding customer service!Highly recommend.This was my prior review . Now Ive got to know Robert, i can tell you that he is a rip off ARTIST!He will find a way to scam money from you as he did me . I was late catching on ....BUYER BEWARE!

Awesome! I had my engine replaced and they gave me not only the best price out of 5 other places I called, I also got the best engine and warranty, not to mention, a new battery for free! Robert really worked with me and answered all my questions making sure I got the engine I wanted. I highly recommend!

The staff was very courteous and knowledgeable. Very thorough with the diagnostic process and honest about the needed repairs. Family owned and operated. Turn around time for my car was awesome as well. Id recommend this place for your auto needs..

I was on I26 on Friday afternoon and my car wouldn’t accelerate properly. CarMax suggested this mechanic. They went out of their way to fix my car by the time they closed so I could resume my vacation. The owner went to pick up the parts I needed to make the repair. They worked with CarMax so I only paid my deductible and was on my way. My car has been running great since then!

Outstanding work and customer service Overall: Would Recommendwoke up one morning, tried to go to work and my axle went out on me.looked up the closest place with good reviews and decided to go with Palmetto Auto Service.It only took 2 days and they kept me posted on all the repairs and recommended some which I took him up on.Everything went smoothly except for a minor hiccup which was taken care of for free.

It literally hurt me to even give this place a one star. After today’s incident (17 Aug 2018) and REFUSING THEM from working on my vehicle after a horrible customer service experience from their front desk lady who apparently doesn’t not even work there? But refused to give me her name and hung up the phone on me after I asked when my car would be done. She told me over the phone as I quote “you’re car will be ready when it’s ready” what kind of words are those to give to customers ? She seemed very uneducated and disrespectful.DO NOT, I REPEAT DO NOT GO TO THIS PLACE!!!!! Rob, and ALL the workers are horrible people. I am honestly scared to drive my car because who knows exactly what they did to it. He told me he was going to do a tire rotation but it is not on my invoice either.Oh they will also not give you your vehicle when promised.After they told me my car was ready, I had to wait an ENTIRE HOUR for them to give me my car back after paying and everything!!! Who knows what they did to my car, I’m taking it to another place and getting inspected ASAP!The following pictures are screenshots of the video when the guy kept shutting the door on me while I was waiting for my car (i was standing outside) These people are INSANE. I tried STOPPING them from working on my vehicle and they refused to stop working on it, pretend to finish the job and did NOT WANNA GIVE ME MY CAR BACK. Opened the hood and plugged cords into my car AFTER they said it was finished and after I told them several times to NOT touch my car and stop working on it.THEY DID NOT WANT TO GIVE ME MY CAR BACK AFTER I HAD PAID FOR IT AND THEY SAID IT WAS DONE.THEY ONLY GAVE ME MY CAR BACK BECAUSE I CALLED THE POLICE!!ROB and his employees are all unprofessional!!!ALSO: IF you are military DO NOT GO THERE. They do not care about your schedule either.Worst PLACE EVER!!!!

I will proudly give my money to this family owned business. They always take care of their staff and customers. The are honest and their prices are fair. We will be back, just hopefully not too soon.

Had to have struts installed and a alignment done. When I tell you my car drives like a brand new vehicle again it truly does. Thanks again for a job well done!!

Amazing service! The quality of the work and customer service keeps my family coming back. I left a family mechanic whos been servicing our cars for years to give Palmetto Auto Service my business. The location is convenient, the prices are fair and they stand by their warranty.

I am very selective when it comes to anyone working on my vehicle. I dont dont just trust it with anyone. Robert and his team are very knowledgeable and made me feel right at home. They fit me in their busy schedule and had me in and out in no time. I found my mechanic. Thanks Robert.

The service here was amazing & genuine from beginning to end; I highly recommend Robert and his staffs services to many others for automotive work!They repaired my exhaust system and replaced my oxygen sensor all at a reasonable price as well as in a timely manner!#savedmeTIMEMONEY & ADDED a PROMISING WARRANTY!Thanks folks!

Awesome! These guys work fast and know exactly what they are doing!My dads truck was giving him problems and he wanted it fixed pretty quickly. They arranged to get it towed to the shop and, within 24 hours, had a diagnosis ready. It was the alternator. I went to pay for it and they already had it in the bay working on it. The truck was in and out in two days! I couldnt have asked for better service.I would definitely recommend these guys to anyone!

Excellent service. Busy shop. Friendly staff. Had the Jeep in and out for a new clutch. Price point was perfect. Robert is an automotive enthusiast and they were actually excited about the job. Will be frequenting Palmetto Auto Service for any of my maintenance needs.

Amazing owner and staff!! I am new to the area and came in with noises in my steering wheel and brakes. The owner, Rob, graciously gave me a ride back to work right up the road because I had no one to pick me up. Laken (sorry not sure of spelling) at the front desk was polite, reassuring and beyond helpful. When my car was diagnosed they called me to let me know about everything before they started the work. They had all the parts and fixed it the same day!! Because I had a rental and no way to pick up my car Rob and Laken brought it to my work!! They are amazing and I HIGHLY recommend them!! I have never been treated so respectfully by an auto shop before. I will call them anytime I have an issue. 😊

Great experience everytime! They are personable and always willing to help. Plus they have always had my car fixed up the same day. I would highly recommend them!

I love the service at this place. Its in a convenient location and they are very knowledgeable and prompt with their service. Robert is an excellent owner and operator.

If you are looking for top notch service, then Palmetto Auto Service is the place to take your car. They are nice and professional and their prices are fair and reasonable. This is the only place I will take my cars! I would definitely recommend them to anyone!

My experience with palmetto auto service was amazing Robert and his team make me like I was right at home. I would highly recommend them. Not only was the people friendly but the environment was too and they will be getting my business 😋😋😋😋😋

Took my 2013 Mercedes in with a problem with my power steering. Had been told it was a major repair by another shop. They fixed it for half as much as the other place! Very pleased with the service.

I called Robert at Palmetto Auto Service after another shop (a chain about 2 blocks up the road, which shall not be named) messed up my truck. I had taken it in for a number of issues, one of them being the driver-side door on my 94 pick-up. When I turned the key, nothing would happen... not only did that other company not fix the door (after 3 tries totaling more than 6 hours), but when I left, I realized they had inflicted the same problem upon the passenger door!Palmetto Auto repaired both doors for me on the very next day! The driver-side rod had to be bent back into place, and the passenger-side rod had to be fabricated from scratch. The guy(s) did great work, I enjoyed a movie while I waited in the lobby, and the price came in at about $350 (parts + 3 hours labor). Unlike the other shop, Robert kept me posted as they worked and as they diagnosed issues, and he also let me know mid-way through that the quote was a little off due to the extra work of fabrication. He didnt surprise me with a bigger bill at the end, and that counts for a lot. 100% without a doubt, I will be back the next time this old truck causes me trouble.

Awesome! Customer service was perfect. They provided the towing service and made everything smooth for me. I will recommend them to family and friends.

Great service and very professional ... went for an oil change and it didnt take to long they did a great job. The guys there are very personable and they take their jobs serious

Amazing service and personable staff/owner. Very informative and direct- will give you the truth about your repairs and offer the best option.

I just brought my car and was freaking out about all the small issues that I was having; especially the fact that my tire pressure light was on. My dealership referred me & honestly that was the best referral I have ever gotten.The team was extremely welcoming even had me laughing while through my inspection. The mechanics and owner went above & beyond giving my car a full diagnosis finding out that my compressor was broken. The owner was able to get all repairs & parts covered by my extended warranty, ordered & installed by the next afternoon. Going even further after i explained that I didnt have any way to work; the owner extended to me a ride to work all the way in Garners Ferry Colombia.I couldnt express further my appreciation for the great outstandingly amazing fast, detailed customer service I was extended by this family owned business. I would recommend Palmetto Auto Service to all my friends & coworkers HANDS DOWN 5 star customer service. Six stars if I could add one. Lol Thank you!!-Niya Martin (St. Andrews Columbia SC)

Thought they were good and my car seems to run worse. I paid $1500 and between a fuel pump, battery and alternator. I asked for a print out of my diagnostic and was told I would get one only for them to tell me that my diagnostic is what they did to my car. Ive been driving for 20yrs and this is not my first car. When you pay for a diagnostic test done Ive ALWAYS received a print out. This guy tells me that not only am I not getting one but that ALL shops dont give them out. They lied and now Im short 1500 dollar. I wish I would have just bought it over to Chevy where I will be bringing it from now on. THEY SUCK.

Fast and honest work. Service is great, workers are friendly. Great place to get your car looked at.

I have received work at this shop before on several different vehicles, only difference between the work I received and other people is that I dealt with the honest techs at this shop and not the dishonest owner. You Robert definitely need God in your life.

Lakin is AMAZING. I hope I spelt her name right... She is patient, understanding, kind, and extremely efficient. She went above and beyond to answer questions that Im sure are outside of her job description and she made sure she effectively communicated the repair and warranty rental process to me.Even after the repair was done she reassured me that they would spend extra time to make sure it was fixed correctly because I have had bad experiences before.If you dont get the same experience as I have had with Lakin, you may need to assess how you approached her because she is 100% the definition of exceptional customer service.This business is blessed to have someone like her to deal with the craziness of their industry.

Great honest people who do meticulous work for a fair price!

Quick and efficient Services

Im thankful for this place, love the owner and his staff they always have my car right each and every time

Went today to have a.c. fixed. Called this morning and it was fixed by lunch. The receptionist was very friendly. Definitely recommend this place.

Thank you Palmetto auto service for the awesome work and great warranty 2years 24k mileage warranty on parts you cant beat that

The staff at Palmetto Auto Services are professional, fast and friendly!

I bought an oil change coupon from Groupon and called the store to schedule an appointment. I work during the weekdays, except Fridays which I work until noon. I asked them to give me a time on Friday afternoon but they told me they dont do oil change in the afternoon! Finally I got an appointment on Saturday. I drove all the way to the store but surprisingly the store was closed.

They helped me and my son get off the road had someone pick me up and had me back on the road the same day im very grateful

Excellent customer service, they handled everything from the tow to the repair to the warranty. I would recommend them to anyone. I was out of town and they managed to take some of the frustration out of my car breaking down.

Robert was very friendly and answered all of my questions. Hands down the best mechanic shop Ive been since I moved to Columbia.

Honest Mom and Pop mechanic service. Labor is standard cost, but theyll give you a fair price for anything that you need.

These guys at the real deal! Diagnosed my car quickly and handled everything professionally. I will use their service in the future! You should to!

Great service, prices reasonable

Super awesome ppl and knows how to make ppl feel welcomed

Best place ever ! they know their stuff inside and out

SCAM SCAM SCAM THIS MAN ROBERT IS A CON ARTIST DO NOT TAKE YOUR CAR OR ANYTHING ELSE TO THESE PEOPLE YOULL REGRET IT THEY WILL TAKE YOUR MONEY AND MAKE OTHER THINGS GO WRONG ON YOUR CAR JUST TO GET MORE MONEY WHY HE IS STILL IN BUSINESS PEOPLE ?ITS NOT BECAUSE HES A GOOD MECHANIC BUT BECAUSE HES A GOOD CONARTIST AN KNOWS HOW TO SCAM PEOPLE. ...BY THE WAY ROBERT IM A LAWYER SO YOUR TALK ABOUT SLANDERING YOU,GOOD LUCK ITS CALLED A REVIEW FOR A REASON GOOD PEOPLE JUST DNT MAKE THINGS UP ABOUT A CAR SHOP SO I WILL BE HAPPY TO SEE YOU IN COURT IT WILL BE MY PLEASURE I WILL TRY TO CONTACT EVERYONE THAT YOU HAVE SCAMED IN THESE REVIEWS TO COME TO COURT WITH ME .....AND ME AND MY FAMILY STAY BLESSED THANK YOU SIR ..... PLEASE STOP LYING TO THE GOOD PEOPLE THAT COME IN FOR GREAT SERVICE IT ALL WILL COME TO THE LIGHT SOONER THEN LATER

Went here to have a new clutch installed, 6 months down the road it went out again. I took it back as it was still under warranty and was told it needed a whole new transmission because something in the transmission was messing up the clutch. Well I finally got around to letting another shop look at it and its nothing wrong with it besides the slave cylinder which was supposedly replaced at the same time as the clutch. Will never take another car here again!

Very quick service...helpful...great work

Very nice... Fast.. Friendly..thank you

Great customer service, very professional, and repairs was done in a timely fashion. The technician was very knowledgable about my vehicle and I would recommend this shop to my friends.

Prompt, experienced and explained everything - I wish I could say the same about Drivetime. Very good experience with Robert and Debbie.

Treats his staff like they are beneath him. Talks to customers like they are nothing more than another dollar bill he is cheating them out of. Treats and talks to his pregnant girlfriend that is at the shop all the time like a rented mule he uses when ever he wants something out of her. Also over charges customers for work he hasnt done to their vehicle. For instance charging for a fuel pump and only putting a gas cap on. Oh i dont know maybe charging thousands of dollars on a certain persons vett shall I go on? Please think twice before you trust this shop!!!! Techs are great but owner not business savy at all.PSS.Its not slander when it the truth sir. And please I dont know who u you pray to but it isnt our Lord cause he dont let people like yourself do this to other. So be assured I will pray to the Lord above for you. May God bless you Robert Balentine.

Great customer service. Very honest mechanic, which is not always easy to find. Never tries to upcharge you on services that arent needed.

Very fast service. I really enjoyed my visit

Thank you for helping me in my time of need

On May 10, 2017, I took my car to Palmetto Auto Service with a front headlight and indicator light on the left side of the vehicle not working. I was advised by the owner, Robert Ballentine, that he would need to perform an electrical diagnostic in order to determine the issue. The cost of the diagnostic was $100. I was skeptical of this, but I did agree to it. A few hours later, I received a call from the owner stating what he believed to be the problem. He informed me that the headlight harness adapter needed to be replaced, which would cost approximately $600. He requested I pay him $300 in advance to guarantee the work, as well as cover the purchase of the parts that were necessary for my repair. I provided Mr. Ballentine with my credit card number to cover the advance payment and he informed me that he would have to order the part, which would be in by Monday (5/15). Further, he stated that he would be able to fix the car by Tuesday (5/16). On Tuesday (5/16), I called the shop to check on the status of my car and I was informed that there was some sort of new complication with my vehicle. They ran another diagnostic on the car and I was told that apparently the computer module in my car was fried and they were doing a search for the part to fix this issue. On Wednesday (05/17/2017), I called the shop again to check on the status of my car and Mr. Ballentine asked me to sit down due to the severity of the issue. He explained to me that the part to fix the computer module, as well as the labor to fix the issue was going to cost me an additional $800 (on top of the $600 that I already incurred due to the initial issue). At this point, I have spent $600 on repairs that did not even fix the issue, as my front headlight and left side indicator light were still not working. I decided not to have him fix the new issue related to the computer module, which essentially left my car in the same condition as it was when I brought my car in for repairs on May 10. When I went to pick up my car on May 17, I asked Mr. Ballentine for a print-out of both of the diagnostics that were run on my vehicle. His initial response to me was that he did not have one. I questioned this response, as I have always been provided a copy of any diagnostics run on my car when I have had previous issues. As a result, he printed me a repair order that was dated the same day I pick up my car, as he did not have an official diagnostic report. At the end of the day, I left the shop having spent $629.41 on an issue that he stated he detected, but with a car that is in the same condition as it was when I took it in for repairs on May 10. I am extremely frustrated with this situation, as I believe Palmetto Auto Service was misleading and tried to scam me into paying for services that were unnecessary.

PLEASE DONT TAKE YOUR CAR OR TRUCK TO THIS SHOP ROBERT IS A CON ARTIST AND WLL SCAM YOU OUT YOUR MONEY YOUR CAR WILL BE WORSE WHEN U LEAVE HE MAY SEEM TO BE NICE BUT ITS ALL APART OF THE SCAM TO MAKE YOU TRUST HIM SO HE CAN RIP YOU OFF STAY AWAY FROM THIS SHOP HE WILL NOT STAND BY HIS WORK PLEASE FIND A DIFFERENT MECHANIC THEN ROBERT PLEASE PLEASE PLEASE IM WARNING EVERYONE.

Good local business, smart in their troubleshooting, repairs and great attitudes

SCAM! SCAM! SCAM! THIS PLACE IS A RIP OFF! ROBERT WILL TAKE YOUR MONEY AND MAKE YOUR CAR WORSE THAN BEOFRE YOU TOOK IT IN! PLEASE DO NOT TAKE YOUR CAR TO THIS SHOP! IM TRYING TO HELP AS MANY PEOPLE AS POSSIBLE SO PLEASE BEWARE !!!!

Robert is a good dude that knows his stuff!

In and out same day and awesome price, i had went to another shop before hand and they gave a super high price . Palmetto auto service did a diag and save me lots of money with a cheaper repair that was the actual problem and very honest

Over priced my diagnostic test.

Palmetto Auto Service always provides exceptional service at a reasonable price, whether it be a routine oil change or a major repair.

Great service, friendly staff, clear explanation, I recommend them highly.

I would call this place a hidden treasure. I came in for a routine oil change. I was in and out in less than half and hour.

They really helped us out when our car wouldnt start. Fair price, and fast!

Im glad i have someone that i can go to on the regular and they always take care of my car

Quick oil change and nice people

Palmetto was very professional. My car was ready in a little over a week and it only took that long because of the warranty company. Robert stayed on them untill he got results. Now my a.c. is blowing like it never did before.

Quick, cheap, and super polite

Love this place,,, awesome mechanic repair shop

Owner is a liar .. after being caught in the lie he still tried wouldnt own up

Fairly priced

Friendly and knowledgeable