Seems like this thing just inhales the gas. Granted I am coming from a 94 jetta, but still. I cant get the trip computer to show less than 13l/100km no matter how soft i drive the car around the city. I can actually almost visually see the fuel guage move down LOL. OK Maybe I am stretching it a bit, but man is it ever thirsty.

Any comments would be appreciated, thanx.

 

Any idea how that relates to mpg? I get 25 mpg or so on average in my 03 se.

 

Don't trust the onboard L/km gauge, reset your trip odo when you fill up and calculate your actual L/km used the next time you fill up. (it was real hard for me to not say "mileage" in there )

 

I converted 100km/13L and it seems it says he's getting 18mpg which is definitely low. Mine says I'm getting 25mpg everywhere when I know I'm not .

 

Same here..
I usually shift at 3k rpm and by the time i'm at 60mph i pop it into 5th or 6th... i get about 250 a tank in the city
more if i drive on the highway...

 

One, Canada...they use some sh1tty gas for winter fuel. Two, this car goes through gas in cold weather like a frat boy goes through beer at a keg party. If you leave it to idle/warm up for even 15 minutes or so, your mileage will suffer severely. Three, regular scheduled maintenence. This includes getting the tires to the proper inflation levels. For some reason, this also has a large effect on this car. Four, do not, under any circumstances, rely on the cars onboard computer/trip computer for accurate information. Only one case in about 20 is it even close to correct.

 

What do you guys recommend as a good tire pressure in winter? I am currently running around 31-32 last time I checked. I should probably also get winter tires as well, any suggestions what might be a good tire for this car? BTW, thanx for the reply's regarding the gas milage, for a second i thought there might be something wrong with my car

 

2-3 mile trips will kill mileage in cold weather. My gas gauge dips fast the first 15 minutes of my commute.

 

Get rid of the RE92s if they are still on!!! Anything else is better...

 

I have the Hankook tires - H405 Ventus HRII . Not bad when it is not snowing. Happy with them so far for the price.

 

Those tires have soft sidewalls, so you could safely increase pressure to 35-38 psi (don't ask in Kpa), not lose ride comfort and get "slightly better" mileage.

 

Overinflation of reinforced sidewall tires causes a loss of contact patch area, so yeah, you'll get better mileage at the cost of slightly or significantly less overall tire traction...

 

Were are not talking about g-force KD sidewalled tires here... 5 psi is the difference between cold and hot tire pressures and won't make that much difference, especially on the Hankooks

 

Be that as it may, if you continually run higher pressures in your tires than what is the manufacturer norm, then you'll notice the center section of the tread wearing more than the outer edges. Even at 5 PSi over (continually)...

 

For whatever is worth, I ran the crapenzas at 35 psi all around from they one (95 miles on the clock. The stealer never set the pressures right and they were at 44-45 psi when I checked them the next day).

All four tires had 4/32nds left at the sides and center when I replaced them at 57,734, to be exact. It won't make an iota of difference.

 

Slight pressure difference won't make a a hill of beans difference, and that's where you're right. Running a cold tire 5-6 PSi above normal (when it actually means running 10 or more PSi above normal when hot) makes a huge difference. I've seen it time and time again. It's why most of the Potenzas and Turanzas that come stock on the Maxima only last 25K-30K miles, even when properly rotated and balanced. It's because they are over inflated by 5-6 (or more) PSi (and that's cold, mind you)...

 

I only suggested a 3-5 psi increase. 10 psi increase when hot??? Even if that's true, which would only be if the tires are underinflated not at normal pressures, that would bring the tires to 45 psi, well within the maximum pressure recommended by the manufacturer. (Tirerack claims the first 20 minutes the increase is about 5 psi and less than 1 psi after that. http://www.tirerack.com/tires/tirete...l/pressure.jsp )

 

Keep in mind that the specs on tire pressures are based on cold tires and they account for the pressure increase as the tires heat up. Always fill your tires while cold and you will be fine.

 

I hate it when Tirerack posts articles that are so damn vague. They give you just enough info to be dangerous.

They didn't mention anything about compund type, sidewall type...nothing! The article is based on what the average person should do with their average tire on the average car. If you replace your tires with something that has a better gripping compund, then they are going to heat up more and cause more fluctuation. Some compounds get stickier when driven over distance, some will actually lose grip when driven long distance, and some are in between. Anyway, the point is, there is no simple solution for tires and tire pressure. Pressure is totally dependant on the individual tire manufacturers and their specific products in a given application AND for specific situations. Whew...what a load of crap!

Cliff notes - Do exactly what the tire manufacturer wants for your specific tire and specific use application...

 

Rule of tumb: The lower the tire pressure, the higher the operating temperature. No matter what compound.

Rule of thumb 2: Smaller contact patch, better winter traction (which is what Blaharo needs)

Re Cliff notes: so I can't dress up my Falken 512s per their warranty requirements? Never mind I'm running those POS tires at 47 psi cold. Kids, don't try this at home...

 

I agree...probably the cold weather up there causing extremely long warm up, which prolongs the ECUs dumping extra fuel for coldstart enrichment, ie worse gas mileage.

If I lived in an area that got extremely cold, I'd get a block heater of some type and rig it to a timer for the AM starts.

 

good idea! ya that weather here blows, was -40 windchill couple of days ago. At least it is encouraging to know that the milage will improve come summer time. As for the tire pressure, I'm just going to leave em at recommended psi for the max. I doubt its going to make much of a difference anyway, these tires suck in snow as it is.

 

What do you want for $70 US a tire?

 

Smaller contact patch never equals more traction...if you mean narrower or wider, then that's one thing. Besides, contact patch size stays constant with street tires anyway. It's a matter of physics...

 

1) Smaller contact patch means higher ground pressure. Higher ground pressure means better traction, when compared to the standard patch size, in winter conditions.

2) So, if the contact patch stays constant with street tires, why the higher tread wear in the center of overinflated tires? Physics?

 

Check JCWhitney...they have a couple different versions from a oil pan warming pad to a dipstick warmer. Not expensive at all.

Another "trick" you might CAREFULLY try is to block a bit of the radiator fins with a piece of cardboard or better something that won't deteriorate.

I've also seen some more elaborate block heaters that circulate the coolant through a heater to keep the block from freezing, however I'm not sure how that works or how expensive.

How long does it take for your car temp gauge to rise up to the "normal" middle-ish position?

 

That's your reinforced sidewalls for you, distorting your middle area tread. Did I not mention that before? Nevermind, I see that I just touched the topic and didn't go into it fully...

Anyway, the patch size stays constant as far as total area, and you can see that very well when the car is sitting still. Spin the tire at high speed and see what happens (harder to see)...the reinforced sidewalls maintain the tread pattern near the sidewalls, and the center bows outward due to centrifugal force and added pressure and air. It does this b/c it's not reinforced (the center section). The sidewalls remain pretty much constant in most of your inflation levels. Lower overall pressure causes the sidewalls to take up the slack of the center section, which slightly bows inwards (despite centrifugal force), removing some of the center section tread from the rolling contact patch. This causes more wear on the outer tread sectors (where as too much air causes too much wear in the center tread sectors).

Damn it, so much for trying to simplify things for everyone...

So yeah, that's physics on both rolling and sitting tires. Want me to go into cold and hot stuff as well?

 

PLEASE please don't get QuickySliver going...he is the tire GURU around here now that y2kse is gone.

J/K Quicksilver...I always learn from your tire posts, but they always point out another dumb@ss thing I was doing with my tires.

 

It's just years of experience, both on racing and street tires...(that includes some rather dumb a$$ mistakes and misconceptions on my own part over the years)

I just wish I could conduct seminars on this stuff. People are so easily misled by places like Tirerack, NTB, etc etc etc. Those guys/gals just sell and service tires...nothing more. They do not design, build, and test them. Neither do the folks that sell or market these tires to places like NTB, Tirerack, Discount Tire Direct...etc.

Believe me folks, when I post something like this on here, it's not just to toot my own horn and "tout the clout" or what have you. It's because I want each and every one of you to be educated, and to be safe when using these products. That's it. Ask Ford Motor Company and Firestone about their little SUV stupidity that's been going on for years. Remember all the rollover incidents with Explorers/Expeditions and other related vehicles? I'll give you a little hint...the tires used in most instances were never meant to be used in the manner they were. So who's fault would that be? Ford's, or Firestone's?

 

All I can suggest is to get a second job to pay for gas or ask your boss for a raise. I have an 03 Max and I know exaxctly what you are talking about. Gas stations love people with Maximas and SUV's.

 

If you're up for it, you could put together a "Technical Article" for the Shop Talk home page "Reading Room" like SteVTEC does.

I'm sure SprintMax would host it.

 

That is true for premium tires, but not so in the newer segment of "performance tires at a fraction of the cost." Cheaper tires have less reinforcement on the sidewalls (marketed as "rim protection..."). In this case the size of the contact patch patch will vary under both static loads (depending on the air pressures) and dynamic loads (air pressures, latteral, longitudinal and vertical forces).

 

You realize BEFORE your posts *I* used to inflate the tires on my Max stock Potenzas to 41psi or so religously for better fuel mileage and what I thought would be less wear during all my hwy mileage.

Once I read the risks involved and the OEM R&D that went into picking recommended(ignoring Ford) pressures, I lowered them down. Immediately of course, I had a softer/quieter ride, my biggest complaints about Potenzas and most of all handling grip was improved for a bit of turn-in sharpness. Trade I was willing to give.

Now all my vehicles and the ones in my family use as close to OEM recommendations as possible except it's a bit of a guess once you go with non-OEM tires.

 

Where did you quote that from? Also, list some of the specific tires you're talking about...

Actually, we shouldn't be whoring up the thread like this on this side topic.

 

Sounds like one of yours.....

 

Too late for whoring... Personal observations. You name them, Hankook, Falken (not all, obviously the ST Sports aren't), Avon, Cooper.

Which contact patch is bigger? same tires, different pressures:

 

I average about 10 litres per 100 km (03 SE 6sp). Not sure what that is in mpg, but then again who cares. As for sh1tty Canadian fuel, I haven't noticed any difference in the winter. My trip computer usually registers around 8.3 l/100 km. The trip computer is definitely off.

 

wow, not bad, do you do a lot of highway driving?

 

I drive a mix of highway and city. I've had the car for about eight months and I don't really notice a difference between mostly highway trips and mixed trips. Your original post states that your trip computer is indicating 13L per 100 km, I would strongly suggest that you set the trip odometer when the car is empty and then, on your next fill up, record the mileage and how much fuel you used. This will give you a more acurate reading.

I'm not sure if your Max is an auto or not. My co-worker has an auto V6 Altima and he burns much more fuel than I do. Also, my investment advisor has an 02 Max 6spd, he tells me that he can get below 7L per 100 km on the highway on extended trips. I'm a little skepticalof that claim.

I'm interested to hear how much city driving you do and whether or not you have a six speed.

By the way, for winter tires I bought Khumo KW17 and they are great. Much better in the rain and snow than the Craptenzas.

 

I haven't used any of those tires...which sucks. My mother used to use Cooper tires, but I didn't do any testing or observations on them. I've used predominantly Michelin, Goodyear, Continental, Pirelli, Firestone, Bridgestone...something that I can't remember on my truck right now...lots and lots of the regulars. Hankook's come on some Infinitis, IIRC.

As far as the contact patch goes (your pictures), they look like similar tread pattern (so I can assume it might be the same set of tires). But beyond that, it's too hard to say. Contact patch is measured at rest (that's the normal way to do it), and it would be all but impossible for me to measure it at driving speeds. I don't have the equipment for that type of measurement. The top set looks to have left more rubber behind, but it could be because it was at half the speed as the bottom one. In short, it's impossible for me to tell just by looking at those two pictures when I didn't get to see the launch/braking, speed, all the other variables involved.

Once you start taking out reinforcement, you have lose stability/protection when cornering (and for performance tires, this is a very bad thing). But...they still have the DOT/NHTSA (NHTSA Report Number DOT HS 807 805) approved ratings for load, so the fact that they have less doesn't mean that this affects how the contact patch touches the road, or how the tire operates (based on it's ratings). If anything, it may actually lighten the overall tire up (which could be good for some performance)...

It just sounds like they trade off the factors of rigidity and longevity for the factors of cost and weight, which would lead me to believe they have less useful life overall. Is this not the case with these types of tires? Michelin Pilot Sports have a long tread life (if maintained properly), and will outlive a similar set of say Sumitomo Tires (HTR+) over the same driving circumstances. Yet they maintain similar load ratings and performance capabilities. They (the Sumitomos) cost at least half as much as well, and weigh less. It sounds reasonable (and I can use my brothers SLK for info since he used Sumitomo tires on it, and had Michelins on it before that).