Tried an experiment. I've been messing with gas additives and when I completed that and pick one I continued, but this time the experiment moved to tire pressures. Wife’s car, 850 Volvo wagon, tires Yok Advid TRZ’s commutes 350+ miles week, sometimes over 450, all freeway speeds from stop and go to 80+ mph. Mileage with 40psi is 26.5 over about 4 tanks. Mileage at 36psi was 25.75 over three tanks. I would need more tanks but that looks like almost 3% and I don't want to go keep it at 36 because of the better mileage at 40. I curious what other might see if they try about the same spread in tire pressures.
Tire pressure and mileage.
- Thread starter Lonnie
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I have had similar results of 3% mileage increase running pressure at 40psi vs 36psi on my Dunlops. I just had some 215/65/16 Cooper CS4 tires installed on my 03 Caravan 3.3, but haven't had to drive my "usual" 1000 miles per week yet, so I haven't been able to tell if these tires are capable of similar mileage. They are quieter at speed and have better wet traction than the Dunlops so far.
Don't try significant overpressure with low-profile high performance tires. The centers will wear unevenly....and quickly. Then you'll be deducting the cost of new tires from your fuel economy savings.
Sounds about right between the factory 36 psi and the results from running my 97 960 at 40 psi. I got about 1 mpg difference when I raised the air pressure by 4 psi.
I have not seen any wear problems with the air pressure increase.
I have not seen any wear problems with the air pressure increase.
I am not above the MAX setting on the sidewall. Also I think that the bulge in the center of the tread from higher pressures is an over stated problem. With a set of Michelin’s with a max rating of 44, I ran them at 40 and got over 60k on tires that I was told were only good for 40k miles. Running modern tires in the mid range settings is too expensive form me. I think the tire is more stable in handling and braking with the higher settings as well.
Was this a general statement or concerning the Avid's? If it was concerning the Avid's, I wouldn't call them a "high performance" tire. But, just about anything you run with pressures exceeding the side wall will wear the centers. I ran a set of All-Seasons(Goodyear American Eagle - Walmart special in a 185-65-14) 50,000 miles at 44psi all around (max) and didn't have the first sign of uneven wear. I also got WAY more mpg than the "expected" (1993 Toyota Corolla, 1.8L).
My truck tires (OEM Firestone HT's 205-75-15)are around 36-37 (29 recommended) and other than shoulder wear from cornering, the centers are wearing just fine.
My car tires (225-45-17) are 40+ (32 recommended)and have very even wear. As a matter of fact, I'll have 45,000 miles on them at replacement. For reference, they are Goodyear Eagle F1 DSG3's with a treadware rating of 280.
My truck tires (OEM Firestone HT's 205-75-15)are around 36-37 (29 recommended) and other than shoulder wear from cornering, the centers are wearing just fine.
My car tires (225-45-17) are 40+ (32 recommended)and have very even wear. As a matter of fact, I'll have 45,000 miles on them at replacement. For reference, they are Goodyear Eagle F1 DSG3's with a treadware rating of 280.
I have found the pressure recommendations (on the vehicle not the tire), to be too soft, and the tires wear out too quickly.
I suppose they want maximum ride quality.
If you stay under the max tire pressure, you should be fine.
I suppose they want maximum ride quality.
If you stay under the max tire pressure, you should be fine.
My BMW calls for 34F/38R "normal loads" in all parts of the world except the USA and Canada. The tires are rated at 51 PSI max pressure, so that's not a problem. For North America the recommended tire pressure is the same as R-O-W "Max Load" = 44F/48R.
Tire wear with 245/40 fronts and 275/35 rears seems unaffected by the high pressure. Ride gets a bit bumpy, though.
I'm guessing that the higher pressure is to provide assistance with the "Corporate Average Fuel Economy" numbers.
Tire wear with 245/40 fronts and 275/35 rears seems unaffected by the high pressure. Ride gets a bit bumpy, though.
I'm guessing that the higher pressure is to provide assistance with the "Corporate Average Fuel Economy" numbers.
On my VW Jetta I still have the stock tires, Goodyear Eagle LS 195 65 R15 (44psi sidewall max) tires. The recommended pressure is 26psi front/rear for half load and 30/41psi front/rear for full load. The car is rarely gets fully loaded so I run 28psi.
At 26psi (recommended half load) I got about 22-23mpg city and 28-29mpg highway. Easier to make smoother stops and feels like more control.
At 30psi I got about 24mpg city average, probably just a little better fuel economy with 30psi. Car seems to roll easier.
I tried 36psi on a highway trip once and got 32mpg. Ride was a bit more bumpy and had to use a little extra effort to make smooth stops. I found above 32psi is a little too much and does not gain any significant fuel economy.
The recommended 26psi is a little low but nice ride. 28-30psi seems to work very well, good fuel economy, handling, even tire wear and good braking. Back then when I knew nothing about tire pressure I was running like 20psi and got horrible gas mileage ~20mpg city, bumped it to the recommended 26psi and got to where its supposed to be ~23-24mpg city and ~30mpg freeway. Back when I drove to school I drove the same route all the time so I was able to test different tire pressure vs. fuel economy.
At 26psi (recommended half load) I got about 22-23mpg city and 28-29mpg highway. Easier to make smoother stops and feels like more control.
At 30psi I got about 24mpg city average, probably just a little better fuel economy with 30psi. Car seems to roll easier.
I tried 36psi on a highway trip once and got 32mpg. Ride was a bit more bumpy and had to use a little extra effort to make smooth stops. I found above 32psi is a little too much and does not gain any significant fuel economy.
The recommended 26psi is a little low but nice ride. 28-30psi seems to work very well, good fuel economy, handling, even tire wear and good braking. Back then when I knew nothing about tire pressure I was running like 20psi and got horrible gas mileage ~20mpg city, bumped it to the recommended 26psi and got to where its supposed to be ~23-24mpg city and ~30mpg freeway. Back when I drove to school I drove the same route all the time so I was able to test different tire pressure vs. fuel economy.
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2004 honda accord lx 4 cylinder recommends 30 psi front and 29psi back. This worked fine when has original michellin energy mxv4 s8 tires which are one of the best tires for low rolling resistance and fuel economy. I changed tires to michellin exalto AS and got about 3-4 mpg less with same air pressure. I put them at 34 psi front and 33 psi back and mg improved about 2-3mpg. They handle so much better than original tires, but need higher psi to offset some of the loss of fuel economy.
If Avid's go 80k miles at the hands of my wife, they meet my definition of a high performance tire.
40f/36r in Mazda, 36 all round in Outback, Nitrogen fill.
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