Im not sure if the oil is my problem, but I'd thought I'd ask here. I have a 2007 RDX and I just had my first oil change on it done. Nothing else was really done on the car that day. I put in Pennzoil Ultra Platinum 5/30 and a new filter. Now since the oil change, my gas mileage is 33 percent less then before. They say that Pennzoil is HTO-6 rated. I can physically see my gas needle go down on short drives. Not sure what else to check really. What oil are you guys using in your first Gen RDX?

 

I've always stuck with the +/- 4500 mile oil change interval using Mobil 1 5w-30+Acura oil filter with my 08 RDX (purchased with 30,000 miles, still on the road with +200,000 miles w/ daughter). My combined mpgs were always around 17-17.5 mpg stock. I did see an improvement with combined mpg when I added Hondata reflash and ETS intercooler to 18.5 - 20.5 (20.5 mpg combine when temp were below 40 degrees F).

 

I've put all kinds of brands in the car over the years (Pennzoil Plat among them), never noticed any issue as long as it is synthetic 5w-30. Last couple changes have been Kirkland brand since they had a stupid good sale a while back.