jfluhr

I also have a 99 with similar miles and mileage. The mission at this stage is to maintain rather than lose mpg---mine slowly and steadily went to 12 at which point it was rough idling and just had the check engine lite kick on...I checked out this forum, disconnected the battery to reset the light and: 1) checked sp wires 2) new plugs 3) changed air filter 4) changed pcv valve 5) changed oil 6) cleaned the maf sensor 7) cleaned the tbi and iac 8) correct tire pressure 9) fuel system additive After, the mileage was restored and the rough idle and check engine light went away... plus the acceleration and performance improved. Collectively, these repairs made a world of difference and saved an expensive dealer visit... all are monitored regularly nowadays. Nick/Las Vegas ← I get around 15 mpg in the city and 19-20 on the highway. I agree that the cold weather probably contributes to the poor gas mileage. I found that using premium gas adds about 2-3 mpg so its worth the extra $.10/gallon, plus if you have a Sam's Club nearly, premium gas is only about $0.05-$0.10 / gallon more expensive than regular unleaded at the other gas stations. My question though is regarding this routine maintenance. Did you perform all of this mantainance on your own? How do you check sp wires, spark plugs, pcv valve, maf sensor, and how do you clean the tbi and iac? I'm not even sure what the maf sensor, the tbi or the iac are. Is there a form you could direct me to? I have recently changed the oil and air filter and routinely check the tire pressure. Thanks. Jason

Shortly after I purchased my 2001 RX300 I had the transmission fluid changed. My mechanic flushed the system by filling and draining the system 3 times with the Toyota transmission Type IV fluid. My question is: Was it necessary to flush with the Toyota fluid, which increased the cost of the tranny flush significantly, or could a cheaper fluid have been used on the flush and then refill with Toyota fluid? Also, is it necessay to flush the system every time you change the tranny fluid, or can you simply drain and refill? Thanks, Jason.

Thanks for your help. I have switched off the overdrive while driving to make sure it works, and it does indeed increase the rpm when switched off, so I know the overdrive is working. As for the gas mileage, I've only run about 1.5 tanks with the premium fuel because I didn't know any better before then and I used 87 octane for my first 2 or 3 tanks (not quite sure what the previous owner used obviously). So hopefully, I'll continue to see my gas mileage increase. If not, I suppose I should take it to the dealer and have the O2 sensor looked at. Tire pressure is at around 30 psi. One last question I forgot to ask last time. My transmission causes quite a jolt at times when I switch from reverse to drive. Could this be a warning that it needs to be looked at? Thanks again!!!

I also recently purchases a used 2001 RX 300 with about 39K miles. I love it so far, but I have a couple of questions. This is my first SUV so I'm not familiar with the differences in gearing from a sedan, which I've always driven. I've noticed that at highway speeds (65-75 mph), it runs at around 3000 rpm. Is this normal? I'm used to my sedan running around 2000 rpm at that speed. Secondly, I just drove it about 600 miles this past weekend, the first time I've driven significant highway miles. It got about 19-20 mpg with premium gasoline. I've been reading about some people getting 22-24 mpg. Mine is an AWD, so I'm wondering if these people who are getting 22-24 mpg have a FWD? Is 19-20 mpg about right for an AWD, or could I possibly be due for some maintenance? I replaced the oil, tranny fluid, brake fluid, engine air filter shortly after I purchased it. Thanks a lot!!!