Clean Ride!
So cool to see an unmolested HX ...
EGR and Fuel System clean work wonders. You should see a nice bump.
Are you running synthetic oil and LRR tires?
A/C takes a huge hit on Slambo's (my '99 HX) numbers. Thankfully, it's been mild here in Jersey this summer, and I've been able to run A/C off for the most part. (I haven't done any documented A/C on/off tests yet.)
I've come up with an upper grill block that's wicked easy/clean. Waiting for cooler weather before bolting it in. I tried one lower grill block experiment while it was cooler.
I'm keen on lowering.
... as long as you have good roads ...
Slambo rolled off Craigslist and into my driveway with cheap-o eBay lowering springs and a front strut brace. The suspension's a bit stiff, but handles remarkably well. The rear tires are positive cambered (top in). If all goes as planned, I plan to swap in a real set of springs, along with new shocks and other components.