jrfiero

It just KILLED the mpg!

I just pulled a 5x8 cargo trailer ~1000 miles, halfway loaded, halfway empty, all highway.
The RX did fine, plenty of power, brakes worked well (fortunately I never had to test them hard). On a smooth road you hardly know the trailer is there. On less-than-smooth roads you can definitely feel it's there. I have a wheel imbalance somewhere, I expect on the trailer, which I just bought used two days before the trip.
But it killed the mpg - I got 17+ loaded, 18+ empty. 65mph max (which meant I was about the slowest thing on the road).
Its a 2980lb GVWR trailer (880 empty) but I'm sure I didn't have it loaded close to that (Haulmark Transport DLX). It's tall though, about a foot taller than a 5x8 U-Haul, so the aerodynamics aren't great. I towed a U-Haul on this same trip with my 2001 Highlander and got 17mpg loaded.

Recently installed Curt 4000lb Class III hitch worked fine, as did the wiring/lights. I do need to find a drawbar with no drop - I used a 2" drop, and the tongue, loaded, was down just a little. No towing problem, but it left the jack foot kinda low, and it dragged going out of (and back into) my driveway. A couple inches might fix that.

Just another Lexus experience!

Jonas

ericsan13

Let's say halfway loaded trailer is 1930 lbs. RX 450h AWD curb is 4652 lbs. Total weight would be 6582 lbs.

So wouldn't you expect to see a 29% reduction in the 28MPG highway? This reduction would mean 19.8MPG average, not including any aerodynamic losses which would be significant at 65mph.

This may be bad math though. So, did you carry anything fun?

jrfiero

Just a bunch of furniture for our next year retirement house, and shelving materials for the storage unit.

But no, I wouldn't expect a 29% decrease in mileage. IMHO, that was bad math .
The aero has much more to do with it, I think, than weight at constant hwy speeds, and as you mention aero is significant at 65. I can't bring myself to go slower ('cept when the limits are much lower).

My V6 Highlander got around 22-23 on the road and it only dropped to 17 with the trailer, so I expected the hybrid to do better than that.

I think the shape of the RX exacerbates the aero issue with the box trailer, more than the upright back end of the Highlander, because the RX lets more air slip down to smack into the front of the trailer. I was looking into some aero aids for the trailer today, since I'm going to be making numerous trips, but nothing jumps off the (web)page.

Jonas

User 41924

I would tend to agree, that it's more areo that weight. Also, I would think that towing would impact a hybrid more than a non hybrid, simply because you're going to be using the ICE a much higher percentage of time (as well as more power when you do) to overcome the increased drag. It would seem to me that being a hybrid almost wouldn't matter.

Not that I'm an expert! Just OK at rationalizing

jrfiero

Moderators -

I don't think I started this thread in the Hybrid section.

Although it is about towing WITH A HYBRID, I think the info is at least as much about towing as about it being a hybrid.

I rarely come to the Hybrid section - I look first to the 3rd gen RX section. Most things in that forum apply to Hybrids as well, not true in reverse. I expect non-hybrid owners rarely if ever look here.

I respectfully request you move this thread back to the main 3rd gen RX forum.

Thanks,
Jonas

kitlz

Jonas, it was moved to the hybrid forum to avoid confusion. There are enough differences, mileage being one of them. So your towing experience won't apply to 350 owners.

CometVR4

Towed my motorcycle (500lbs Ninja ZX-14) 600 lbs with our old 400h and I achieved 22mpg with a small motorcycle trailer. Cruising speeds were 75-80mph.

Did the same trip towing with my Infiniti FX and got roughly 14-15mpg. I

jrfiero

Anita -

I respectfully disagree.
There is the title and one sentence about mileage.
There are comments on the Curt hitch, how towing feels (with the same gas engine), differences with a tall trailer vs a U-Haul - the majority of it is about towing, independent of it being a hybrid. I don't think readers of the forum will be confused, but by having it in the "Hybrid Technology" section they won't get any benefit. It certainly isn't about "technology," and many posts in the 3rd gen forum are about hybrids, like many of the trailer hitch posts.

Jonas

CometVR4

Hybrid and gas RX are different animals. Weight is different, brakes are different, steering is different and of course gas and electric motors. A regular RX350 would not be the same and just by fuel mileage an RX350 is averaging 18-20mpg without the trailer.

If I were to start a topic about the AWD system I wouldn't want it in the regular RX forums because they're different systems.

If you were talking about heated seats or nav system, those aren't really hybrid specific.

kitlz

Jonas, CometVR4 pointed out most of the differences I was referring to in my previous post but did not list. I would add a few more, like horsepower. The 350 is 270 HP, the 450h is 295 HP. How much that extra HP compensates for the 300+ pound weight difference, I couldn't tell you. Probably the only way to find out would be to do a side by side comparison. The 450h is also part time AWD, part of the design to make it fuel efficient, and has the ability to turn eco mode on and off. There's more but I hope you can see why it would be beneficial to keep this thread in the hybrid forum. It makes sense, just like having separate gas mileage threads. The 350 folks can't relate to our experiences all of the time.

markrivers

Jonas thanks for the info

as for the speed limit when towing, here in California, it's 55mph and CHP will ticket you if you do 65 or higher.

Three60guy

jrfiero and kitlz

You are both right. In my 20 years of forum management I learned over time that the best policy is to try not to micro manage the intent of the users. The success or failure of the forum ultimately can come down to perceptions. In the scheme of things whether this particular thread is in one location or another isn't all that terribly important. What is important is to foster the good will and intent of the users.

Just my 2 cents.

Cheers

jrfiero

7000 miles with the 450h & trailer, half loaded, half empty.
Never did better than 17mpg. mostly worse. Basically the same loaded or empty. Mileage reduced by wind, even though the towing wasn't noticably affected.
Recently bought a 2003 GMC Safari to do the towing. It's a slug compared the RX, and, of course, gets even worse mileage, but on regular gas!