I have a 2003 XC70 (140k miles) and a 2007 (50k miles). Last weekend I happened to drive both cars and noticed how much slower the 03 accelerates, so I timed each 0-60. The 03 took 11 seconds on average and the 07 less than 9. Now that I focus on it, the 03 may have always been slower since I bought it 4 years ago with 90k on the odometer. Both have been maintained by Volvo specialists on schedule. Same engine, same weight. 03 burns no oil and runs very smoothly. Gas mileage same in both. One or two ignition coils replaced in 03 a couple of years ago, and turbo vac line replaced recently. Where would you start to figure this out?

 

You never say where you are located and the EPA has recently approved the sale of e-15 gasoline..with 15-20 percent ethanol rather then 10 percent.

 

No idea where to start. Are they both running the same type of plugs? You '03 XC should have the LPT so it should have a better 0-60 time than that but if you have no other issues don't worry about it.

 

I have the same problem but at 6,000 ft altitude on my 2000 V70R. It takes forever to get going sometimes, and at other times it takes right off. I have been told that it is a software issue and that an update or reprogramming will fix it.