Say what you want about 03/04 4.6's but they got acceleration where you 4.0 folks don't.

Then you can start the premium vs. regular fuel debate. And yes retarding the timing does have its effects.

Don't be hatin' on the 4.0 lol! Who needs quick acceleration in Alabama anyways? As long as it gets where I'm going and pulls anything I want to pull I'm happy. LOL!

I experienced the same sensations, even with my GPR motor installed. I changed all 4 O2 sensors (they were the originals and had 140,000+ miles on them). It made a noticeable difference in acceleration, plus greatly improved my fuel economy.

your GPR motor also has a non-stock cam

I'd have to get up to 90 again to see the RPMs, I think it's around 3200 or so.


MPG is between 0 and painful, I don't go 90 to save gas :)

thanks kfx- yeah, after that 'sweet spot' there's no more oomph in the gas pedal. I floor it and the engine rev's like all get out, but the truck ain't moving any faster.

"sport mode"- aha! yeah, my concern is mostly for safety. especially accelerating from a dead stop and trying to pass vehicles on the highway. looks like taking the 'long view' before passing would be best. not looking for fast, just trying to learn the truck's performance characteristics. thanks all...

I'm with @Dave03S. No issues with my 4.6. It's nothing like my Jaguar XJR mind you, but I have no problems passing, or climbing hills. I've got plenty of hills around here too.

Even when pulling my small trailer with a buggy in it, I run 80MPH to Reno with a full load of camping gear and people, and I still get 14.1 mpg and all the power needed. I'm not racing or anything, but I also like to keep moving... If you've ever run HWY 80 from Sacramento to Reno, or HWY 50 from Placerville to Reno, you know about the hills. They are the real deal. :D

PS: That's with my 265/75-16's on it. I actually gained performance in my opinion when I up-sized a bit.

You must be crazy to drive at 90 mph in that kind of vehicle. Firstly it's not very stable - if you need to make any kind of high speed manoeuvre, it'll easily flip over. If you have a blowout at that speed, the chances of survival are slim. Secondly the braking distance at that speed is about a light year.

Slow down for god's sake.

If you make any crazy maneuver over 50 you'll roll, no difference going 90. If you have a blowout over 50, you'll likely crash too, certainly at 65 which is why I run BFGs not retreads or knock-off tires. If your truck is not stable at 90mph than you may need new bushings/shocks/springs. Braking distance is not much different at 90 than it is at 65, there's so much wind resistance that as soon as you let off the accelerator at 90 you're down to 65 in a couple seconds without touching the brake.


But please, keep going, I love getting advice about driving over the internet!

Sure, here's some more advice :

Your e-mail is full of scary misconceptions.

Energy is proportional to the square of speed. That means that the energy of the vehicle is DOUBLE at 90mph, vs. 65mph, and 3.5 times greater than at 50mph. Work it out for yourself. Also using a braking distance calculator, it is also about double at 90mph vs. 65mph, at a spectacular 380ft.

But the real issue is that these vehicles have a high risk of rollover. Now the risk of rollover might be the same at 50mph, but the consequences of a rollover are not. At 90mph you have 3.5 times the energy to dissipate into the vehicle structure.

Finally what about your responsibility to other road users? Don't they have a right to drive in relative safety? When your 2.5 ton vehicle careers out of control what will happen to that Honda Civic that happens to be in the wrong place at the wrong time?

A good driver takes many things into account - the capabilities of the vehicle, the road conditions, and the abilities of others.