petroleum or pneumatic

If the fuel hauling job is delivering gasoline to gas stations, I'd go with pneumatic.
If the pneumatic is hauling dry bulk cement, that's an easy job, but don't see how the pay would be as good as gasoline.
If the pneumatic is dry chemicals or food grade such as flour, then I'd go with pneumatic.

There's a company name of Savage that delivers diesel to locomotives. Those drivers work hard because those locomotives stay thirsty.

 

I've done lime/flyash/cement and the pay wasn't too good weekly. Maybe it's different in your area.
Where is the diesel delivered to?

 

I'd probably go with the diesel. That hazmat experience will really pay off in the future if you decide to change companies.
I've hauled electrical transformer oil. They pump it out of transformers that are being moved because of the weight. Small trucking companies would buy it and use it for diesel in their trucks. Probably wasn't legal, but was cheap.
Seems everyone involved in moving those transformers drove diesel pickup trucks and that's what they used because it was free and burned good.

 

I've done both. I made a lot more in a pneumatic but that's because it was more hours and I had a union benefits deal. I did only cement products delivering only to our company locations. However, depending on where you are in the country, dry bulk can slow way down in the winter months. Fuel is pretty consistent year round. Out here in California, dry bulk never really slowed down. If the pay, benefits, and consistency are the same, I'd go dry bulk. It's very easy and laid back. It's also a lot less stressful- you have powder behind you, not 9,000 gallons of fuel.

 

The petroleum job will be a more steady income than will the pneumatic. Cement, fly ash, and lime are used in construction, and so the demand for them will vary with the weather and the construction market.

 

Transformer oil is a very highly refined mineral oil. And it definitely ain't cheap when it's new - the last gallon I bought cost me $10 about 10 years ago.

Old transformer oil (produced before the passage of the Toxic Substances Control Act in 1979) can have PCBs in it. I'm not making any accusations, but if I had a bunch of PCB-containing transformer oil and I didn't want to pay a hazmat company to properly dispose of it, I might be tempted to sell it to diesel truck owners for cheap - cash only, of course.

 

The PCB's were in it. Some hotshot drivers used it also. If I was an 0/0 there's no doubt I'd use it. That's a good niche business. Plenty of those old transformers still in use. When towns grow and need to upgrade, they sell the old transformers and buy newer larger ones. Smaller towns can upgrade by purchasing the older , but larger transformers and save tons of money. That's when the old oil enters the underground fuel market. I sure don't have a problem with it; but I don't wear a halo over my head either.