With low gas prices and consumers thinking about summer road trips, June was not a banner month for plug-in car sales.

Two models stood out with dramatic increases from previous months, while others lagged.

The Mitsubishi Outlander PHEV, had its best month yet, after seven months on the market, selling 390 cars. The increase comes in large part because sales have been expanding nationwide, a Mitsubishi spokeswoman told Green Car Reports. The Outlander PHEV is the first affordable plug-in hybrid SUV on the market, following in the vein of cars like the BMW X5 xDrive40e and the Volvo XC90 T8 PHEV, which cost almost twice as much.

Canadian reader K's new Tesla Model 3

Canadian reader K's new Tesla Model 3

The Outlander PHEV has 22 miles of electric-only range, plus enough space inside and a gas engine to make it practical for long weekend or vacation trips. It costs between $36,000 and $43,000 before a tax credit of $5,836.

The other big news, of course, was Tesla's announcement that it built 5,031 Model 3s in the last week of June and delivered 18,440 of the cars during the second quarter. That works out to deliveries of 6,147 Model 3s per month, almost double the sales of the Chevrolet Bolt EV, the next highest selling electric car after Tesla models.

DON'T MISS: Tesla Model 3 production reaches 5,000 cars in last week of June

Tesla also announced that it had delivered 7,433 Model S and Model X cars for the quarter, working out to a rate of 2,477 per month.

For the first time in three months, Chevrolet also released sales numbers for the electric Bolt EV and the Volt plug-in hybrid. Chevrolet sold 3,483 Bolt EVs during the second quarter, for a rate of 1,161 per month and 4,336 Volts, or about 1,445 per month. During the first quarter, the pure electric Bolt EV outsold the Volt.

High incentives on the Volt may have pushed it over the top.

2018 Chevrolet Bolt EV

2018 Chevrolet Bolt EV

In April, GM said that it would join Tesla as the only other automaker to report sales quarterly rather than monthly, making it hard to compare sales of those companies cars to those of other automakers.

Several other popular electric cars saw sales dips in June, or couldn't match previous sales records.

Nissan sold 1,367 Leafs in June, down from a sales record of 1,576 in May.

2018 Nissan Leaf SL

2018 Nissan Leaf SL

Toyota sold 2,237 plug-in Prius Primes, down from 2,924, still about a third of the sales of the standard Prius hybrid.

Honda sold 1,445 Clarity Plug-in Hybrids alongside 126 Clarity Electrics. The Clarity PHEV is the closest competitor to the Chevrolet Volt.

Ford sold 604 Fusion Energi plug-in hybrids in June. The C-Max Energi is out of production, and sales are winding down with only six sales for the month. 

CHECK OUT: Battery-electric vehicle versus plug-in hybrid: why having both makes sense

Sales of the Porsche Panamera e-Hybrid models dropped to 168 for June from 275 and 265 for the previous two months.

Volvo, Mercedes, and BMW did not provide breakouts for their plug-in cars by our deadline this month, but those models don't come close to the sales numbers of the highest-volume plug-in cars.

With the Model 3 approaching full production, the latest sales report demonstrates that Tesla sales dwarf almost everything else in the market, with the exception of the Chevrolet Volt and Bolt EV, and the Prius Prime. 

In the end, we chose a Prius Prime

In the end, we chose a Prius Prime

With the two largest manufacturers of plug-in cars publishing sales results only quarterly, it gives a skewed picture of the for plug-in car market to publish monthly reports that leave those manufacturers out two months out of three.

For that reason, Green Car Reports, will also report plug-in car sales quarterly going forward.