Will Gas mileage improve once a certain amount of miles are put on the motor? I have 500mi on my h3 (base with 265's) and I'm still only getting around 260 on a full tank. I've read on other forums where people are averaging 350+ miles on a tank, wondering if I will ever see that.

 

If you are getting 11.3 mpg then something is wrong. I have never seen less then 15 mpg. What is your tire air pressure?
Yes, gas mileage and hp figures usually get better around 5,000 to 10,000 miles. I would try Mobil 1 5-30 for slightly better mileage also. Sure the parking brake is off?

 

Most of my miles are driving in NYC will little to no open highway miles. My last tank was 265mi. and it took 21 gallons, so I got 12.6 mpg. I'll check tire pressure tomorrow, if it's ok and my next tank is the same as my last I'll bring it to the dealer to see whats up.

yes the parking brake is off[sm=goodidea.gif]

 

ok, didn't feel like waiting till tomorrow so I just checked air pressure. All 4 tires are at 31 psi. Door sticker says 30 psi but tires say 44 max psi. Should I put a few more pounds in?

 

Yes!..inflate your tires to at least 35 psi (cold)..The sticker says 30 becuase that will give you a softer ride, but they fail to mention at that low pressure, the tires will wear out faster and give you poorer gas mileage..don't forget the spare too..as the Tire Pressure Monitor (TPM) also looks at it.

 

Impy,

I got 10.8 on the first tank, averaging low 13's now mainly LA city driving after 1600 miles. It does not seem to matter if I gun it or drive like Morgan Freeman. Just bumped the tires up to 39psi from 30psi and it looks like I will do about 1 mph better.

 

I just replaced my tires with a more aggressive tread but stayed with the stock size. At 35 psi the tread centers would be hot after a short freeway drive, or a surface drive across town. Also, if I drove over some dirt on the road, only the center would pick it up. I dropped them to 30 psi and the temp is much cooler and more even across the tread, but now the TPS comes on until the tires warm up. The ply layers are the same bewteen the two tires, so if you do increase your pressure, keep a close eye on tread wear.

 

Linus what brand did you get? Any pics?[sm=feedback.gif]

 

Not to contradict you Linus, but I think you're fooling yourself into thinking they are running cooler at a lower pressure...In fact it probably should actually cause more heat and wear and tear on the tires, becuase of the higher friction factor...Rather than go into the physics of it all, just think about the Firestone dilemma, when they were having the premature blow outs right and left..Come to find out, the final analysis proved that the tires were UNDER inflated and was causing heat build up in the tire, which resulted in tread separation and failure...Any tire maker of credibility will tell you that inflating to the maximum safest tire pressures allowable for a given tire, will give you 3 things;

1. A firmer ride

2. Cooler running tires

3. Longer tread life and more even wear across the tread face.

 

Dennis,

Not to be contrary[sm=dontgetit.gif] [sm=badbadbad.gif]but if that is true why do the Cup cars on sundays need 3-10 laps to come up to speed based on tire pressure being to low. I have heard DW say the pressures in some cases are in single digits. I used to run BFG AT's at top psi 10 years ago and they ended up looking like a bald guy after 15000 mi, (I did it because I put a lift kit and tires on a manual steering base model).