I'm Mark and I currently drive an 2002 INFINITI Q45 Sport.
I bought it w/40k in 05 and today it has 183,000 miles on it. I drive alot (40k a year) and at least 60% of that is freeway. THe Q comes with an info screen as part of the package. MPG and tire preesure are some of the readouts.
I have always been interested in mpg.
My first car in 75 when I left for college, was a 66 mustang
- with the 200ci straight 6, auto tran and a 2.87 rear end ratio!!!!
Since I wasnt going to be "burning rubber" with that setup
, I got interested in mpg.
In 1977, I actually bought an aftermarket "scan gauge' thingie and installed it inthe console. I ran headers and a slightly 'taller' tire and got 27 mpg on the road all day long.
fastforward 30 years......
My current car, THE Q, lists epa at 16/23. I currently get 25.5+ on most road trips. I got 27mpg avging 70.3 mph, from sacramento ca to salt lake city a yr ago.
I have done the following:
1.) run 255/45/18 instead of the stock 245/45/18. it's 3.4% diameter more, thus lowering the rpm at speed. I also run 44 psi when on the road. (part of the Q's information system is a read out of tire presure) If I'm staying in town I drop it to 38 for comfort.
2.) Removed rear suitcase muffler. (probably wieghed 25Lbs!) install short light glasspacks. there are 2 mid mufflers already so the sound change is minimual.
3.) Installed x-cross pipe in middle of exhaust system where two pipes from the cats went into one. then went back out to two!
4.) change oil & fiter every 4k miles and airpreesure clean the air filter everyweek.
5.) built custom lower air duct that feeds into stock air box.
6.) I installed a IMPUL FULL BODY kit. lowered the body lines 2 inches all around the car. Did not nessecarily do this for mpg...I just REALLY liked the look!(
....
)
5.) DRIVING STYLE: this car weighs 3801lbs, has 340hp V8 and is capable of 0-60 in 5.9. It can also keep pulling past 129mph.
BUT.......It also has a sweet spot in the tourgue curve that allows it to get pretty good mpg when driven with a sense of awareness.
I actually am already doing some of the driving techniques the this site and others recomend.
My last trip to texas (1700 miles 2 1/2 days ) I averaged 25.8 mpg at 70.2 mph.
Also, I alwys run the a/c. I ran an A-B-A test with windows down and lost 4mpg.
I am very active on 2 different Q45 sites. THere are hardly any aftermarket bolt on preformace parts for the 4.5liter V8. In fact, everyone who even tried CAI always went back to stock because performance suffered. THis particular engine really has been tweaked to its best from the factory. Also, the electronic control modual for the engine 'adjusts' itself and the trans ecm 'learns' your drining style. I credit the trans ecm for part of my good mpg scores
I am VERY interested in getting to the next level. (30 + mpg) THe underbelly pan and the grille block specificly are of interest to me.
I am very impressed the level of knowledge and conversation that I have seen so far.
2002 Infiniti Q45 Sport w/IMPUL body kit:
removed rear muffller:
RIght lower air duct:
coming into hole in bottom of factory airbox:
information screen:
