Well, what are they? MVS Forums member (hey, it’s free, why not register?) j-dawg and the rest of the crew answer this important bit of Volvo trivia.
This is actually one of the more interesting bits of P80 lore, to me. No idea why.
98- cars don’t have the electronic throttle, VVT, solid lifters, as do (most) 99+ cars. 99+ cars use cartridge-style oil filters, where as 98- cars use canisters. if you were looking at a turbo, 99+ cars have engine oil coolers on the oil pan instead of in the radiator. 99+ T5s switched to the 16T turbo instead of the 15G that i think the 98s got. 99+ cars have a revised radiator design that still cracks. 99+ cars use a mechanical timing belt tensioner, whereas 98- cars used a hydraulic tensioner. the 99+ tensioner is more finicky, from what i’ve heard.
1998 vs. 1999 Changes & Differences