can a 215/45R17 be used to replace a 225/65-17 tire

Except for the part that mfr's "adjust the number" I would agree. I just don't know how they could since the test process is fairly controlled under the UTQGS and is auditable by the NHTSA. If it was discovered they fiddled with the test parameters or results during a Firestone-like investigation I'd think the mf'rs credibilty would be ultra shot. Lawyers love such revelations during liabilty suits.

The point about comparing apples and oranges is so true... all the way down to individual drivers' results. I could get vastly different results from the same tire you have, on the exact same car! There's just so many variables: tire pressure I operate at and how attentive I am to maintaining it, driving style, roads I use, weather conditions, and on and on.

And, finally: some tires will invite "abusive" driving while others don't. All this makes it very hard to make any kind of comparison. I could get very different results my self from one identical set to another... and I have as it happens!

The rating is only a guide, but it's the best thing we have as consumers, IMHO.

hi group- 2 weeks ago i picked up a 2001 SE, which seems to be, for the most part, a very nice car. (i previously had an '88 SE that i drove the piss out of... gave it away with nearly 250k miles and still running strong).

Anyway... on to my problem. the inside of the rear glass fogs heavily overnight (to the point of dripping), even with the windows cracked- it also does it with the windows up overnight. this is in so. cal.- no rain, pretty dry & warm the past few nights. Only the rear glass is doing it- not the sides, sunroof or windshield. I haven't been running the A/C (i've actually been driving with the windows down for the most part) so i don't think it's caused by the evaporator drying off.

Any ideas what might be causing this? Thanks!

That's not necessarily the case. The speed rating is not an indcicator of wear, it's really only the wear rating. The reason you see many people with hi rated tires wear them out often is because high performance tires are usually built with softer, better performing compounds.

This is the general rule of thumb I use:

Hi wear rating = 400 = not very sticky rubber compound. It will last a long time, but you won't want it for the track.

Low rating = 160 = very sticky rubber compound. Ideal for the track, but be ready to change it real soon.

A perfect example of this is the Pirelli P7000 SuperSports. There was actually 2 models of the 7000s, the 7000 and the 7000SS. Exact same tire, but the SS, or SuperSports were made of a hard compound which lasts forever, and the 7000 was made of a sticky compound which wears out fast. The non-SS version gave your car very high G capability but could only last less than half as long as the SS version.

Most people don't know that there were 2 version so they usually juast say 7000 when it was most likely the 7000SS they had. I had the 7000SS as well.

CD

Buddy,

I just searched this out on the net:

"A tire with known wear data is used as a control tire, and the results are corrected for a possible shift in testing conditions compared with the point of departure."

See? Number fiddling. You can bet if they consider the results to be goofy compared to THEIR other tires, they fix the problem. Either by redesigning the tread layer in the critical 6,400 mile part, changing the test conditions, or making empirical corrections based on real-world results with their other tire lines. They don't test against OTHER manufacturers tires.

"The test course consists of three loops of a total of 400 miles (644kms) in the geographical vicinity of Goodfellow Air Force Base (AFB), San Angelo, Texas, U.S.A. and consists of the following protocol: Run a car with test tires mounted till 6,400 miles (10,300kms) pass. The tire is tested in convoy with a "base" tire so as to eliminate the variable of temperature and road surface. Measure the tread depth after each 800 miles (1287kms) run. Then the projected worn out tire life is calculated, using 30,000 miles (48,279kms) as 100% Index."

Rating of 100 = 30,000 miles. Ha. Isn't this enough to lose respect right there?

They go around in circles and then make up a number that only roughly parallels the actual results. I've seen lots of references to "corrections," and this is just not a very controlled scientific process.

Agreed it is the best we have to go on. But a manufacturer's reputation concerning tread wear is a better indicator.

Of course it isn't and I didn't mean to imply it was... I was just responding to his initial question.

Exactly my point.

Good thing to note... pay close attention to what you're buying!.

I'd have to say here it's a matter of interpretation as to what "number fiddling" is :)

My point is, I don't think they will simply change the number to one they like when given a number they don't like at the end of the test (to me, that's number fiddling.)

I'd expect that "corrections" would be rational and based on empirical data (as you suggest). I'd also expect they could stand up under a peer review. The NHTSA can audit the results and levy fines if they are inconsistent in how they do their tests and interpret results.

I understand all tires are run with, and compared against, a standard Course Monitoring Tire as the control.

Hey... I'm not trying to say that this number is useable in a quantitative way (I don't think any one would suggest that) only a qualitative way!

But even with this there's a problem as I see it... different tires by the same mfr. have different tread wear life _by_design_. Check out the experience by Codifus in this thread with Pirelli's. That doesn't make either tire bad for their intended purpose... but if you heard of the low-mileage tire only one might think of Pirelli as a bad risk!

if you heard of

I only think of Pirelli as a bad risk in the rain.

My Yoko dbS2's are rated at, like, 340 or something. 220 is more like it. I don't see the fed's statisticians bashing down their doors.

My experience tells me that this is an area the bureaucrats don't really want to mess with, there are no "solid" answers anyway, and manufacturers have liberty to fudge the numbers. We consumers aren't privy to the exact nature of the "corrections" but the results speak for themselves. It's a better-than-nothing guide, but also another example of how to lie with statistics.

I think that's kind of funny... I don't remember any wet traction problem with the Pirelli's I've had... not that I recall they were good, just no real recollection. I do remember that both sets lasted REALLY long... like 60K miles... I remember replacing them because the sidewalls were so scuffed, ugly and checked I didn't think they were safe any more. But the tread was still OK.

"lies, damned lies, and statistics" (Mark Twain? or Benjamen Disraeli?) True, especially if you don't know what is behind the numbers and how to use them.

Did you check to see if your carpet is wet?

You dont want to know how much those tires cost,,I wish I had the 16 inch wheels an standard tires to - better ride and half the cost.

I spent almost $700 to replace the 4 original bridstones - and that was at Discounty tire with the cheapest 225/17 tires they had (very good BTW, much better ride and handling,,Nittos).

and yes,,burn premium,,mine knocks on reg, and at present gas prices premium is only 8 to 5 percent more than reg....

watch out for the brakes,,they warp and shudder in the front (dealer fixed mine at 25K no charge), and the coil packs, well my check engine light has been on for about a month,,and i am afraid to read the codes,,,, Coil packs, which you can do yourself, are about 60 to 70 each, and you might as well do all six.

Frankly - the coils are a Nissan known design failure,,and should be recalled,,as an emmisi>>

Thanks for all your responses regarding ignition coil.

I called couple of Nissan dealers in the Seattle area (we live in Bellevue) and got different quotes for the same job: parts + labor for replacing all the six coils (range $620-$850).

Any recommendation on who/how to choose ?

Thanks Sams

Hi all,

I just replaced the motor for the power lock on the driver side, which worked fo about an hour...

Now it seems like the current was to high and theres no motion at all, like its melted or something. (had a real hard time unlocking the door...) Does anyone know what might cause this?

I drive a 1992 Maxima 3.0E (european model)

It's a very easy job... taking into account the usual considerations like which of them are more convenient to you and which have a better reputation for getting the car done when promised go with the cheapest.

One thing: let the dealer know you are aware that this is a common problem and ask if you could get it done under warranty. I have read where some people have had luck getting the dealer, Nissan or both to pick up at least a part of the tab for this repair.

You can buy these online for ~$300 a set. They take like 2 mins each to install.

I would check out the trunk area for wet carpet, water in the spare tire well. Possible causes: gasket leaks from the car wash, leaking tailiight assemblies, etc. Maybe the rear body area has been repaired, which you probably don't want to hear. Window and body leaks can result from improper re-assembly. If you have a sunroof, there might be a drain line that passes thru the trunk, but is not draining outside. Good Luck Bob

I just drove home my 02 Maxima with 6spd. I drove it on the highway and in the city. The gearbox is sweet. I never had a problem finding gears. Also, the clutch is nice too. I am able to put the car in 1st at a stop and I can get the car roling without stalling it out. This really saves the legs in serious stop and go driving. I've owned a BMW too and while its gear box had a little better feel the Maxima is quite sweet. What's interesting is that Maxima only put the 6spd in 02-03s so the car is a little unique in that respect. The guy I bought it from did some nice mods too but it was a little loud on the highway.

Hi,

I just bought an 02 manual Maxima. The car is fast, handles great and is fun to drive. The only problem I had with the car is that the car is loud. The former owner upgraded the ECU (Jet), Stillen Intake and a Greedy Cat back. I was wondering if I replaced the muffler would I have a quiter car. I know that I may lose some HP but that is OK. Does the Intake also creat a growl. Any suggestions are appreciated. Would I better off replacing the intake too?

Put the stock muffler and intake back on it.