My F50 has a 8.5s 0-60 - HELP ME PLEASE

[thehacker3]

Okay, so I timed my 0-60 today on a flat road with the engine really warmed up (over an hour of driving) and I got a time of 8.5 seconds. This was slightly uphill and I could NOT believe that the number I was staring at was right so I did it again - two more times. Each and every time, I got an 8.5s 0-60. To me this is devastating and I want this issue set right asap so here are the details:

Engine was really warmed up. I understand this will hinder performance, but the time I got is still ridiculous, isn't it?

I just replaced the air filter 5 days ago.

Replaced the fuel filter last month.

Tires inflated with nitrogen to 32 PSI cold.

Last two fill-ups were 91 premium from Shell. (Maybe it was 93? Should I be filling up with 93 for peak performance?)

Occasionally I have the tire caution light go off but I was told it only had to do with something that the dealership has to do (wave a wand over the tires or something?)

A/C was turned off for one of the runs and it still ran 8.5.

And here is the most pertinent detail imo:
MPG is currently 18.1, but the last 400 miles were straight highway. It's normally 17.6 but it was running really low recently (around 16.5) so I replaced the fuel filter and used 32 oz. in two treatments of Chevron Techron. After that, I believe it went back to normal but I have not done a proper MPG test before/after so I have no reference aside from the onboard MPG meter.

Can you guys please help me out? It really pains me to see this 340hp beast reduced to performance worse than an Altima hybrid.

[djwarner]

Sounds like you have some basic troubleshooting to do - could my many things. First place would be to read the trouble codes. If you don't want to read the blinking lights, most auto parts store will read them for you free of charge.

On a practical matter, while accelerating from a stop at half throttle, do you notice a pick-up in acceleration as the rpms transit through 2500-3000. This occurs when the variable valve timing shifts to the high rpm position. This should be quite noticable.

Driving around the suburbs my F50 gives 19.5 mpg; driving suburban highways with stops every 2-3 miles yields 21.5-23.0 mpg. Normal around town driving, I rarely see rpm's above 3000. Of course, YMMV, but from your description, you should be getting better mileage than you report.

[Q451990]

I think the published spec. was about 6.7 seconds... how hot was it outside and what's your altitude? I know the factory typically tests them at 60F at 0 feet altitude. Heat and altitude will both thin the air and cause noticeable performance losses.

I'm not saying you don't have an issue to resolve - but if you happened to be doing these runs on a 100 degree day in Denver, it could explain a lot.

Heath

[thehacker3]

It was >80 degrees outside yesterday and the car was fully warmed up with over 30 miles driven and over an hour of run-time. I live in Staten Island, NY so it's pretty much 0 altitude.

Published was 6.7 but Infiniti claimed 5.8. I would be perfectly satisfied with a sub-7 0-60 but apparently, even that is too much to ask for.

IIRC, I do believe there is a jump in acc. when the rpms transit from 2.5k - 3k. Are you saying that if there isn't, something is wrong with the VVT?

[qship96]

Infiniti lied.

Published magazine numbers are obtained by unrealistic methods for most adult owners which include power-braking to wind up the revs....not something the average owner who is paying for the maintenance and repairs of the vehicle wishes to do very often, if ever.

[thehacker3]

Infiniti lied.

Published magazine numbers are obtained by unrealistic methods for most adult owners which include power-braking to wind up the revs....not something the average owner who is paying for the maintenance and repairs of the vehicle wishes to do very often, if ever.

Ah, but I did power breaking in my runs as well...

[elwesso]

Was the A/C on? You would be surprised how much power than can rob on a hot day..

Have you checked the codes on the car? Wonder if maybe something is amiss somewhere?

[thehacker3]

Was the A/C on? You would be surprised how much power than can rob on a hot day..

Have you checked the codes on the car? Wonder if maybe something is amiss somewhere?

I suspected the A/C so I turned it off for the last run. Was still 8.5.

Negative on the codes. I want to confirm that there is a problem before I go hunting for it.

Is 8.5 on a 88 degree day with a warmed up engine normal or not?

[Q451990]

Is 8.5 on a 88 degree day with a warmed up engine normal or not?

I wonder how much the change in fuel blends (e.g. E10) has impacted 0-60 times. I'm pretty sure it has a lower BTU rating when it's blended (the cause of the lower MPG), but I have no idea how the ECU deals with it...

Heath

[djwarner]

Yes, the impact of the VVT is significant to getting higher horsepower at higher RPMS.

91 Octane instead of 93 will affect how much the timing can be advanced before knock sets in.

I believe you can still get 93 Octane at Sunoco.

Now you've peaked my curiosity, I might have to take an excursion and test mine.

[thehacker3]

Yes, the impact of the VVT is significant to getting higher horsepower at higher RPMS.

91 Octane instead of 93 will affect how much the timing can be advanced before knock sets in.

I believe you can still get 93 Octane at Sunoco.

Now you've piqued* my curiosity, I might have to take an excursion and test mine.

Yes, I am now tempted to hunt down 93 to run a few tests of my own. If the performance is significantly better, I will officially wave goodbye to 91 forever.

[maxnix]

I think the published spec. was about 6.7 seconds...

Actually it was 5.9 with the first 2002 and the 2.97 differential. Should be as good with the later 3.13.

Uphill is not good for testing. 95 octane is good for the engine. Turn TCS off, do not torque brake.

[maxnix]

Was the A/C on? You would be surprised how much power than can rob on a hot day..

AC clutch should automatically disconnect at WOT.

Ethanol and heat should rob you of a second. No way to judge road grade on internet. Tires? Vulcanized hard?

[djwarner]

Well , I went out on an errand today and was planning on a few test runs on the way home. Just as I was waiting for an opportunity at a red light, my wife called saying I was needed at home.

As a result, I only got to make one run. 91 Octane, AC off and TCS off, 92 degrees at near sea level. Without holding the brakes, I spun the rear tires for about a half second and ended up doing 60 in 8.6 seconds.

I pulled out my aircraft engine books to determine just how much power a fresh engine should be putting out under these conditions. Adjusting for density altitude and temperature ( 40 degrees warmer than standard and a density altitude of 2400 feet) an engine capable of producing 340 HP under standard conditions would produce just under 300 HP.

This number would have to be further reduced for 91 Octane 10% Ethanol. Now lets adjust further for worn plugs, dirty air filter, etc. BTW my car is a 2002 with the lower ratio differential.

This raises an interesting question about your hybrid's performance in real world conditions. The electric motors used in hybrids produce maximum torque at zero RPMS and are not affected by atmospheric conditions. This would lead one to believe that it should retain more of its acceleration potential in warm weather than an equally powered gas engine.

It would be nice if you could verify book versus actual performance in a few other cars.

At any rate, it would appear your Q's performance is not that far off from mine. Back in 2002, real world reviewers were reporting 6.7 second times. I guess ethanol, age, and lower octane are exacting a toll.

[thehacker3]

Glad to know I'm not the only one now!

Will definitely have to give it a go on 93 if/when I get my hands on it.

[thehacker3]

Filled up with 93 and had a couple of runs. Long story short, on 93 gas and ceteris paribus i was running 7.6.

Quite an improvement! I expect that on a cool engine I can make the 6.7 target now.