NikonGuy

iTrader: (1)

Ok, I have a 2008 IS250 RWD (75K miles). My brother in law has a 2010 IS250 AWD (92K miles)

I notice the cars drive a bit different. We both have stock rims, mine are 18" staggered and his are 17".

On the AWD car, the gas pedal is definitely lighter. You step on it and car goes. On my RWD it is heavier with more resistance. You have to step harder for it to move.

Just wondering if characteristics of AWD vs RWD or maybe they tuned things differently from 2008 to 2010.

Jaytea

iTrader: (1)

That's the AWD doing more work. RWD obviously powered by two rear wheels while AWD has torque to all four wheels. This makes the AWD feel quicker and lighter.

vapid2323

I have had a 2006 RWD 350 and now a 2011 AWD 350.

I would take the AWD all day long, for us up here in Washington State the extra grip is amazing when it rains. But if I lived in a place like CA I would prefer the RWD, it can be a bit more fun when the traction control is off.

edgeucated

iTrader: (4)

Its actually the exact opposite. The AWD system is heavier and the robs the car of more power. The AWD is slower and more clumsier than the RWD except under adverse conditions.

What might be making the OP feel that the AWD is faster and lighter is that the ECU learns the way you drive, so maybe your brother-in-law normally drives harder. Also the 2010 has a revise steering ECU.

17 inch rims also make a large difference. Reducing rotational mass will have a huge effect on how a car feels.

FSportIS

iTrader: (13)

+1

I also want to add that RWD is way more fun to drive as it is more tail happy and easier to induce oversteer to do powerslide and even drifting with traction control off.

NikonGuy

iTrader: (1)

So do I just unplug negative battery cable for a few minutes to reset ECU

Also I'm referring to pedal feel. The 2010 AWD was definitely lighter while my 2008 RWD has a heavy pedal (neither cars were set to ECT Power or anything like that, just normal)

FSportIS

iTrader: (13)

10-20 mins is enough for resetting the ECU. Once you did, drive the way you like, pay close attention to the shift points. The computer will start learning the way you like to drive and shift at that point. Overtime, the car will likely shifting at those points.

Another thing is try turn off traction control by holding the trac off button for 5 seconds or so to see if the driving feels different. The car feels lighter and more alive and in my control when I turned it off. Don't drive too aggressive on the street with traction control off though.

knguyenk

An out there question, when were the sparkplugs on each 250 changed? I noticed my 2007 IS 250 AWD started to be a bit nimbler in terms of acceleration when I first did the plugs and eventually the battery (when car barely wanted to start). Even with the same driving style before and after the plugs and battery (ECU reset at each instance) the pedal felt like it traveled less while the car felt quicker (while the weight of the AWD was still present).

But what edgeucated said about the rim size could be a factor, though the staggered 18's of the RWD should give it more grip for better acceleration.

NikonGuy

iTrader: (1)

I bought the cat a few months ago. Carfax and Lexus history indicates it has been regularly serviced (oil, brakes) and water pump replaced at 50k miles. No record of spark plug service though