The owner's manual says something about not driving the 450h off road. What about dirt or gravel roads, such as in national parks, etc.

 

The 2012 manual does mention sand, snow and gravel in several locations here is one:

It's always, well most times, easier for me to use the online manual to find words or phrases than the paper manual. Plus I can do it from anywhere without hauling the manual around!!

 

OP, FWIW, I've driven on gravel driveways and short distances as (hopefully) you intend without a problem on unpaved dirt "long driveways" to people's homes a couple of times in dry weather. I would not hesitate to take my RX to most National Parks, but NEVER into an offroad situation that some offer, e.g here in the West. Our RX's are not a 4WD vehicle designed to go over hill and dale, over sand dunes, through rough terrain or streams and deep mud, and all that sort of extreme environment, including roads that most vehicles or sedans are not intended to travel. I'd generalize this way -- an RX is not a 4WD Jeep or Hummer and should not be treated in the same way some may take them into more extreme situations where other vehicles could not make it -- your RX will do better on harsher road conditions than perhaps your average sedan if you understand what a hybrid FWD or AWD (depending on what you own) is capable of and what it's limitations are in the real world. Just don't go crazy, and your RX will serve you well.

 

Bert makes many excellent points. The only lasting damage, at least for me, from driving on gravel, is paint chips.

 

Driving on dirt roads infrequently shouldn't be a problem. I'd be more worried about the possible damage from flying rocks like DunWkg mentioned. If you take a look at the maintenance schedule, there are additional items that should be serviced/inspected if it's often.

 

Just stay to "maintained" dirt/gravel roads. I remember a post from another forum, someone had a big rock hit their exhaust heat recovery system right by the catalytic converter which is somewhat exposed directly under the vehicle. The part was one big piece, $4200 + install! Damage that and you lose your coolant, so it's not just a matter of a banged up exhaust pipe you can put off fixing.

 

I remember seeing that one too. From the photos it was pretty clear what really happened. The RX 450h (LUX SUV) was never meant to be an 'off road' vehicle therefor the typical off road protection panels were never designed for the car and the words to the effect of 'don't drive off paved roads' were printed in the manual.

But there's always going to be folk that think they can push the limits and survive so ..... I think there's a bumper sticker about 'stuff' happens .

 

Guilty as charged! At least in my old 2nd gen RX350 (which had a higher ground clearance) I very carefully took it a few places I'm sure it was never meant to go. Some pictures on this page:
https://www.clublexus.com/forums/rx-...ml#post7179898

This being Oz, there's an awful lot of gravel roads to traverse, so stone chips are a problem. However the vehicle itself is quite capable so long as you don't do silly things. When I have to go on poorly maintained roads or actually off road I usually hire a Toyota LandCruiser. The main issue is that gravel = dust and it's a real pain detailing the car after getting a load of dust in it.

 

Good golly, yep really enjoyed some of your photos, especially the ones parked by 'bigger' vehicles . Oh, and read some of that 'interesting' family history of your 'great great grandfather' .

 

I have driven my AWD RX300 about a hundred or so miles on dirt roads with rutted and gravely conditions. Having previously owned an old 88 Jeep Pioneer, I am fortunate to also have more genuine off-road driving experience.

My 2003 Lexus handles very predictably off-road. It has a firm suspension which helps reduce body roll and maintain ground clearance. Excellent braking and engine power via AWD help it navigate gravel roads with ease.

As far as off-road driving, biggest considerations are inertia and traction. You can't whip your car around corners, lower traction around corners and inertia will carry you wide or completely off-trail, which might be down a 200 ft canyon.

So long as reasonable speeds are maintained, especially in corners, you should be okay on dirt roads.

Driving in the sand is another animal entirely, and sand will stop even the most intrepid 4x4 vehicle.

I am really itching to take my Lexus to the imperial dunes, just to cruise around on the flats, but I know it really doesn't have the ground clearance to go over even the most modest of crests. Letting air out of the tires is a requirement of course, if you ask me.

I have done very minimal driving in deep beach sand in San Diego, on Fiesta Island. The RX300 handles very well at low speeds so long as momentum is maintained. I have found the limited slip differentials to be very useful, though I am not climbing hills, or trying to drag race anyone.

If you really enjoy driving off-road, I would recommend a 4x4 or different AWD vehicle designed with off-road driving in mind. But if you infrequently get the itch to get your RX300 a little dusty, so long as you have roadside coverage, I say go for it, go for it.

 

...As the rear motor is air-cooled; and the high-load low-speed driving normally associated with what most consider "off-road" (as opposed to "dirt road") driving could be what the engineers want to limit.