Can I deduct the car expenses (gas, maintenance, lease payments, insurance, etc) from my income when calculating the ma’aser?
If these were business expenses then they may be deducted. the reason for this is because this whatever is a business expense is not considered profit, rather the cost of making the actual money and not as actual income. However what is used for private use is considered part of your use of your profit and you can’t deduct for it.
Chavis Yair 224, Aruch Hashulchan Y”D 249-7, Monchas Yitzchak 5-34(6), Ahavas Chesed 2-18 ftnt 2.