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Frequently asked questions

1. What do you think? When will the crisis pass through and how will we understand that it is gone?

The crisis will pass away when the right time comes. We will know when it is gone for sure when a new one starts and we start missing the first one.

2. What is the origin of the fuels that you work with? What type of diesel would you recommend me, would you recommend Lukoil? I am asking because we haven’t been satisfied with the fuels lately.

On the Bulgarian market dominate fuels which are produced by Lukoil Neftochim Burgas.
Their quality is constant and the supplies are regular. On the market there are also fuels which are produced abroad, mostly in Romania, Greece and Russia. Some of them have high quality but unfortunately they cannot be supplied regularly and there is difference between the batches.

3. Hello! Where can I give fuel for analysis and how much will it approximately cost?

The analysis of fuels, in particular diesel, can be done in many laboratories. It is important to know that for official purposes are valid only tests that are conducted in the so-called authorized laboratories – results that are given from such labs can be used in commercial, litigation or other proceedings or disputes. You can find accredited laboratories in Sofia, Pleven, Bourgas, Rousse and other places in the country. Prices can vary quite a lot – from several tens to several hundred leva, depending on what parameters you would like to test. The complete analysis is usually very expensive but you can get accurate information only from the chosen laboratory.

4. Why does the quantity of my diesel never match? What does it mean liters at 15 degrees?

The reasons that the quantity of diesel doesn’t match can be various, but most of them are related to the ways and the appliances that are used for the measurement.
A liter at 15 degrees is a volumetric measurement for the volume of the fuel at a specific temperature, namely 15 degrees Celsius. It is a well-known fact that all fluids, in particular, fuels, change their volume depending on the temperature. That is why it is required to measure using the so-called reference volume, or liters at 15 degrees, in order to eliminate the influence of temperature.

5. Is diesel used for agricultural usage going to be colored from 2010?

According to the amendments of the Law on Excise Duties and Tax Warehouses, articles 33 and 34, only fuels for heating are going to be marked. Most probably, diesel for farmers will be sold as usual and the difference between normal and reduced excise duty will be reimbursed to the producers.

6. How will the fuel to farmers be sold?

With normal excise duty as usual.

7. What should I do to keep the fuel unfrozen in cold weather? I do not want to spend a lot of money on additives but do you think that they are 100% effective?

The most important is the correct storage of the fuel. Preferably, keep it in tanks that are not subject to big temperature variations. This helps not only against the so-called “frost” during winter but also against the formation of condensation in the tank. However, when the fuel is already in the tank of the vehicle and it spends the nights in the open, there is no way to avoid the low temperatures.
The use of additives is a solution, as long as they are appropriate. In fact, at low temperatures (meaning below -15 degrees Celsius, according to our standards) diesel reduces its flowability due to the formation of paraffin compounds. This makes it hard to pass through the filters – this is the so-called “freezing”. Generally, the winter additives prevent the formation of paraffin and improve the durability of the fuel up to a few degrees. Different additives have different effect on fuel but in general, they are useful.

8. Hello! The fuel that we receive is with a different colour every time during the past months – we are keeping samples and I see it. Supposedly, it is from Lukoil but it looks different. Is there a way to know what the supplier delivers to me?

Hello! The colour of the fuel depends a lot on the basic raw material that was used for its production, ie the oil (petrol) itself. Depending on its origin the oil differs in composition and therefore differs visually as well. The most important for the fuel is to meet all the required parameters – this ensures consistent performance, no matter its appearance. This can be determined by analysis but it is difficult to find out its origin. Still, you need to know that each manufacturer uses relatively constant raw materials and therefore the fuel should be fairly similar in appearance. In conclusion, visual differences are typically caused by different origin of the fuel.

9. What is the price of the diesel?

We update fuel prices daily. You can follow the wholesale prices here, and the retail prices at gas stations are visible on the main page and from the gas stations menu as well.

For delivery prices, please contact Dieselor's team via our national phone +359 885 306 305, by e-mail or online through the inquiry form.

10. How can I order fuel from my Dieselor?

Dieselor performs fuel supplies throughout the whole country. You can send an inquiry, place an order or receive information about one that is already made through our national phone +359 885 306 305, by e-mail or contact one of Dieselor's offices.

11. What is the minimum quantity for delivery?

Dieselor makes wholesale deliveries throughout Bulgaria. The minimum quantity for delivery on site is 500 l. The price for the transport is included in the fuel price and is not overwhelming for the clients as it is distributed between the deliveries from the route.

12. Which type of diesel should I choose?

Diesel offers different types of diesel fuel depending on the purposes of use.

For road vehiclesyou need diesel B6 with added biocomponent, for off-road machinery (agricultural and construction equipment) and heating (diesel generators) pure diesel fuel without biodiesel is recommended. It can also be selected with a temperature limit of up to -15*C and up to -30*C.

For diesel engines for vehicles, you can also add the specially developed additive Dieselor OK summer and winter, which improves the performance of diesel engines and has a purifying effect against deposits in the fuel system.

If you need a consultation, contact Dieselor's team via our national phone +359 885 306 305, send a direct online inquiry through the website or by email to

13. Why should I order fuel from Dieselor?

Diesel is a reliable supplier of fuels, proving cutomers with correctness and quality for more than 17 years.

By choosing Dieselor, you get:

  • quality and quantity guarantees
  • transport equipped with modern GPS devices and control methods
  • punctual delivery
  • accurate planning
  • flexible financial conditions
  • web reference for the received fuels
  • reliable and long-term partner
  • professional advice and consultations.

Contact Dieselor's team by email or on our national phone 0885 306 305.

14. What is the right way to add diesel additives to the fuel?

The best way to apply a diesel additive is before refueling.

The additive is first poured into the car's tank, and then the fuel is added.

For wholesale deliveries, it is also a good practice to place the additive and top up the diesel in the correct ratio.

These are also the ways in which we at Dieselor proceed with the cars of our customers at our petrol stations, as well as with the wholesale customers when delivering on site our specialized Dieselor OK additive.

15. How to save fuel?

Many people strive to achieve lower fuel consumption. Here are some of the factors that have influence:

- idling: the frequent starting and stopping in urban conditions increases the fuel consumption. Even just pulling off the road for a 30-second phone call and then turning back in the traffic consumes the same amount of fuel as to turn the engine off and on again. If you are going to stay in one place for a long time, it is better to turn off the engine.

- accelerate and reduce the speed smoothly.

- use a phone or car navigation that tracks traffic in real time and shows you a less busy route.

- free the vehicle from unnecessary luggage and cargo.

- check the tire pressure regularly.

- use the cruise control function to maintain a single speed during long trips.

- park in the shade during the summer so that the air conditioner won't have to catch up afterwards.

- keep the windows closed in order to keep the aerodynamic shape of the car. Driving with the windows open at higher speeds slows down the car.

- get Dieselor's fuel discount card :)!

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