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Checked by people who know
Gas has been our work from day one
Cars and commercial vehicles, LPG and NGV. We know many kinds of equipment, so we can tell you what deserves attention first.
LPG and NGV inspection
Have your yearly gas check, then drive home at ease
Gas vehicles need a check every year before road tax. We look over the system carefully and settle everything else in one visit.
Fully licensed
Gas is about the safety of everyone in the car, not just yearly paperwork
If you are unsure when your tank expires or what needs checking, we go through it with you: tank, valves, hoses, joints and documents, so you feel confident each time you start the car.
Fully licensed
Handled by a licensed operator
Check the document number and expiry date below.
- LPG inspection, cars
- Number
- สปร 357-2562
- Licence holder
- Mongkol Auto Services Co., Ltd.
- Valid until
- 5 Dec 2028
- LPG inspection, transport vehicles
- Number
- สปข 356-2562
- Licence holder
- Mongkol Auto Services Co., Ltd.
- Valid until
- 5 Dec 2028
- CNG inspection, cars
- Number
- สธร 346-2562
- Licence holder
- Mongkol Auto Services Co., Ltd.
- Valid until
- 5 Dec 2028
- CNG inspection, transport vehicles
- Number
- สธข 352-2562
- Licence holder
- Mongkol Auto Services Co., Ltd.
- Valid until
- 5 Dec 2028
Numbers and expiry dates are as shown on the documents held by each company.
No need to go elsewhere
If something needs fixing, the team is already here
We tell you what needs work and the price before starting. Once done, inspection, compulsory insurance and road tax can follow right here.
One certificate lets you renew road tax. The peace of mind on the road matters even more.
Talk to us on LINEGood to know
Which vehicles need gas inspection, and when?
LPG and CNG/NGV vehicles are inspected yearly. Factory-fitted CNG vehicles start from year 4.
| Type | When |
|---|---|
| Converted to LPG | Every year, before road tax |
| Converted to NGV/CNG | Every year, before road tax |
| Factory CNG | From year 4 |
| LPG tank at 10 years from first test | Passing the test extends use by 5 years |
Source: an inspection operator (link). Our engineer can confirm your case.
When does your tank reach 10 years?
Count 10 years from the first inspection and test of the tank, not the manufacture or registration date. See the first certificate. If it has been reached, test it before renewing road tax. Ask us if you cannot find the document.
What is checked, and what do you receive?
Gas system
Tank, valve, lines, joints and leaks, according to the inspector’s list.
Documents and vehicle
Registration book, installation certificate and tank data.
What you receive
An inspection and test certificate, with details for road tax.
What documents do you need?
- Original registration book or a copy
- Installation certificate or previous gas certificate, if any
- Missing something? Send a photo on LINE first
Gas inspection, car: ask for a quote · Transport vehicle: ask for a quote · Tank test: ask for a quote
Real reviews on Google
Reviews from our customers
4.8 stars from 1,143 Google reviews (as of 4 Nov 2026) · All reviews on Google
★★★★★
Brought the car for inspection, NGV gas check and road tax, all done in one place. Convenient and quick.
★★★★★
Brought my car for inspection and the annual gas tank check to renew road tax. The service here is very friendly. :)
★★★★★
Gas inspection, vehicle inspection, road tax and compulsory insurance, all finished in one place.
★★★★★
Good service for gas inspection and vehicle inspection, and the registration renewal was very quick.
★★★★★
Came for a car gas inspection for the first time. Good service, the place is fine, and there's a comfortable waiting room.
★★★★★
The gas and car inspection was faster this time than any time I've had it done before. The receptionist who took my documents and the cashier spoke politely, and were lovely and well-mannered. I was impressed.
★★★★★
All the staff give very good service. It's a one-stop vehicle check for renewing your registration: LPG tank inspection to extend a tank that has reached 10 years, annual LPG/CNG system inspection, car inspection, insurance and compulsory insurance. One place and it's done. Excellent.
★★★★★
I come here regularly to get my gas tank checked. Very good service.
★★★★★
Came for a gas inspection. Good service.
★★★★★
Car inspection, inspection of LPG/NGV gas cars, transfers, registration moves, road tax, compulsory insurance and insurance, all in one place. Good, no need to go to several places.
Frequently asked questions
Must gas vehicles be inspected every year?
Yes. The certificate is needed to renew road tax.
What is a gas engineer certificate?
A certificate of inspection and testing from an inspector approved by the Department of Land Transport, used for road tax.
How much is a gas inspection?
Car ask for a quote, transport vehicle ask for a quote, tank test ask for a quote. We confirm the final price before starting.
How long does it take?
It depends on the queue and vehicle. Send details on LINE to find a good time.
Must a 10-year tank be replaced?
If an LPG tank passes the test, it can be used for 5 more years. If not, it must be replaced.
If it fails, can you repair it?
Yes. Our gas service team explains what to fix and the price before starting.
Do you inspect transport vehicles?
Yes. We hold LPG and CNG inspector documents for transport vehicles. Send the vehicle type first.
Can you renew road tax as well?
Yes, together with vehicle inspection and compulsory insurance in one visit.
Related services
InspectionYearly inspection for cars and motorcycles, then road tax right after.Gas serviceWe find the cause first, then fix what actually needs fixing.Road tax & registrationRoad tax, compulsory insurance and registration work, without the trip to the DLT.Tax calculatorEnter your vehicle details to see the amount.
When you are ready
When does your road tax run out?
Tell us the province on your plate and the expiry date, and we will outline what you need before you come.
LINE
Opening hours
Mon–Sat 08:00–18:00
299/11 Moo 5, Srinakarin Road, Bang Mueang, Mueang Samut Prakan, Samut Prakan 10270, Thailand