I own an S70 AWD, and im aware that it is equiped with the low-pressure turbo (LPT.) I also know that the S70 T-5 is equiped with the high-pressure turbo (HPT)

Can anyone please explain the difference between the HPT engine and the LPT engine???

Lots of differences, not just the turbo. The HPT is a 2.3L with beefed up rods and cranks. The LPT is a 2.4L with the same internals as a NA engine. You cannot just replace the LP turbo with a HP turbo and expect the connecting rods to stay connected :)

Klaus
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Common sense trumps a PhD

Is there a difference as to which engine last longer, or performs better??

Longevity depends on the owner, not engine type.

The NA has 168+- bhp
The LPT has 200+- bhp
The HPT has 250+- bhp

If course, the trim level gets better as the cost goes up with the bhp. If you don't need speed, the NA will give you 30+mpg on the highway, the HPT only 27-28.

Klaus
--
Common sense trumps a PhD

mine just turned over 123k last week. ever since i swithced over to mobil 1 synthetic and been using premium gas, the thing rides/drives smoother than ever.

Valuable finding. The synthetic oil does seem to be amazing. I've used it in my '99 V70 for several years, but I can't tell if it improved fuel mileage.

yes supposedly the synthetic is supposed to we very good for the turbo too, so who knows. i still cant tell whether i should be using regular or premium gas or not, but from using full synthetic and premium gas i find the engine is a lot quieter and smoother.