General Motors sales rose 8.4% in May, riding a seasonal spike in sales to rental-fleet customers and for the third month in a row appearing to overcome negative publicity surrounding the automaker’s record-setting spate of safety recalls.

GM dealers delivered 284,694 vehicles last month, compared with 252,894 in the same period last year, according to WardsAuto data.

Fleet sales accounted for a seasonally high 27.7% of sales. The automaker also enjoyed an extra selling day in the month vs. like-2013, and while year-over-year incentive spending was relatively flat, third-party data shows GM led the industry in discounts.

Nonetheless, GM says May marked its best sales month since August 2008, and it came on the heels of 2.8% uptick in April. The automaker says it expects a market-share increase over May 2013, when it grabbed 17.6% of U.S. sales. GM’s market share at the end of April stood at 18.4%.

“The momentum we generated in April carried into May, with all four brands performing well in a growing economy and 17 vehicle lines posting double-digit retail sales increases or better,” Kurt McNeil, vice president-U.S. Sales Operations, says in a statement.

Last month’s solid sales performance also arrived against a wave of negative publicity for GM, which is on pace to set a record for safety recalls in a 12-month period. In the first five months of 2014, the automaker has issued 29 safety campaigns in North America affecting upwards of 15.8 million vehicles, including exports.

The highest-profile recall involves 2.2 million Chevrolet, Saturn and Pontiac small cars in the U.S. built between the ’03 and ’10 model years with defective ignition switches linked to 13 deaths and 47 crashes.

GM also had a stop-sale issued on several of its newest products over the important Memorial Day sales weekend.

Greg Smith, chief creative officer at The VIA Agency, a Portland, ME-based advertising firm focused on middle-class consumers, says the fallout has hurt the GM brand but not the automaker’s product brands.

“Consumers are doing the research and responding to the product,” he tells WardsAuto. “They are looking for their individual value and since the (2009) bankruptcy GM has successfully shifted the focus to its products.”

GM spokesman Jim Cain cites “product and effective marketing. If there is an impact, it is small and hard to quantify.”

Chevrolet sales increased 10% to 205,010 units, led by a surge in car demand. Deliveries of the Chevy Cruze rose 35.3% to 32,393, Malibu sales slipped 1.2% but held on volume of 19,288 units and the Impala was up 18.6% to 13,348.

Sales of the newly redesigned Chevy Tahoe fell 3.9% to 9,229, while deliveries of its larger Suburban platform mate jumped 9.9% to 5,423. GM says a majority of those SUV sales were with the most expensive trim line.

Silverado large-pickup deliveries finished the month up 3.8% to 46,648.

Cadillac saw its sales edge up 2.4% to 14,688 copies. The SRX 5-passenger CUV had its best May ever, with sales up 22.5% to 4,762.

Buick sales rose 6.9% to 19,957, led by the still-fresh Encore small CUV with 4,475. GMC sales gained 4.3% to 45,039 on the strength of 18,326 Sierra deliveries, a 9.9% increase for the large pickup over year-ago.

So far this year, GM sales were up 2.9% to 1.2 million units and the automaker closed May with 815,897 vehicles in stock, good for a 77-days’ supply compared with 88 at the same time last year.

jamend@wardsauto.com