* Dyno And Facility: MD Automotive
* Testing & Installation: Luke Munnell
2008 LEXUS IS 250
Pros
It's very rare to see an auto manufacturer decrease displacement and power output with the release of a new model. But such was the case with Lexus' launch of the IS 250 for the '05 model year. Not only did the 250's 2.5L V6 4GR-FSE displace 0.5L less than the preceeding generation IS 300's venerable 3.0L I6 2JZ-GE, it output 11 hp less. Despite this, sale of the IS 250 remained high due to increased luxury and accommodation present in the new model, and the fact that only the 250 is offered with a manual six-speed transmission option-what we tested. With so many of them on the road, and considering their lineage, it only makes sense to see how the IS 250 responds to modification.
Cons
Perhaps overshadowed by its bigger brother, the 306 hp IS 350, performance upgrades for the 250 have been debuting at a snail's pace. Three years after the model's release, we had to search extensively for any performance upgrades for the 250, while 350 owners can take their pick of bolt-on upgrades, tuning options, even forced induction solutions.
Notes
Because of its small aftermarket support, and the fact that this month's test IS 250 still happens to be under warranty (as most of yours probably are), we thought it best to install and test upgrades available for it directly from the manufacturer-Lexus' F-Sport package-and an over-the-counter spark plug upgrade that has been proven to increase power in past applications. Not as extravagant as a one-off turbo kit and Haltech tune might be, for example, but also not as costly to our warranty or checkbooks.
Pros
Warranty compliance, ease of installation, direct-fit replacement, OE-spec construction, more aggressive exhaust note, and power and torque gains across the board.
Cons
None, though we're curious to know if further power gains could be found with cold-air systems that replace the panel filter with a cone-type unit and relocate it out of the engine bay.
Parts
Panel filter, air box, aluminum tubing, couplers and clamps, CARB E.O. number, sticker
Tools
Philips and flathead screwdrivers, 10mm socket and extension
Installation Time
20 minutes
Notes
Many aftermarket intake kits for newer cars produce inconsistent power gains, and sometimes even a net loss. Not the case with our F-Sport unit for the IS 250. Initial dyno runs posted only small gains, but after a half-dozen runs, power was up an average of 3-5 whp across the board, with no loss anywhere in the powerband.
Pros
TIG-welded, full stainless steel construction with a burnt tip; straight-through design; lifetime guarantee; deeper, more aggressive, yet mature tone and more power. Fitment was dead-on, and manufacturing was flawless.
Cons
Power increases were modest, at best.
Parts
Exhaust, hardware, gaskets, hangers
Tools
14mm ratchet (x2), WD-40, hanger tool
Installation Time
20 minutes
Notes
In the wake of ever-tightening emissions compliance, our IS 250's catalytic converters (two) are actually part of the exhaust's lengthy intermediate piping. This means our F-Sport cat-back exhaust is really more comparable to an axle-back unit, replacing only the mufflers and small section of piping after the "cat pipe". And since the major source of obstruction in the IS 250's exhaust tract is the catalysts and intermediate piping, not much power can be found without replacing them with larger "test pipes" and sacrificing street legality.