What should my tire pressure be after weight reduction.

Hello all,

Recently I removed my spare tire set as well as the rear seat in my little suzuki sx4 crossover. In the end the car is about 150-170 lbs lighter. I've notice an improvement in fuel economy (2mpg).

My question is should I reduce tire pressure some or is that not necessary? the standard pressure for this vehicle is 33psi all around.

Not necessary. Best approach to tire pressure is to adhere to what is written either on your door sill or in the owners manual

Would you make adjustments to tire psi if you had a passenger because that is well represented by 150-170 weight reduction? I also wonder if you weighed the vehicle before and after or if you are just estimating the number you listed.

stick to the recommended tire pressure.

Huh ? reducing tire pressure gives you better gas mileage ? I run mines at 75 psi ? So if i lower it, i'll get better mileage ? Seriously ?

You fat git. :P

reducing weight gives you better gas mileage, the TC was simply asking if having reduced the weight of his vehicle, should he then also reduce the tire pressure.

it will do the opposite, you will get less gas mileage, and over inflating them has little effect on gas mileage. Best to stick to whats recommended by manufacturer.

Lower tire pressure is going to decrease your economy, not increase it. Softer tires have more rolling resistance on pavement. Stick with the recommended pressure for the tire manufacturer (what's written in the door is for the original tires the car came with).

If you are really concerned with small economy gains, start looking into cleaning up the motor (new spark plugs, engine flush, high mileage oil, get the timing checked/done, etc). That's where most of your economy problems are going to lie. Also, look at changing your driving habits.

What kind of transmission is it? Auto or manual? If manual, do you drive it like a race car, or do you shift as soon as you have enough power to pull through to the next gear? If auto, do you drive it with very soft throttle input or do you race to every red light? Learn about coasting and driving to anticipate slowdowns (if you read traffic, you can end up at the light still rolling through while everyone just spent 10-20 seconds sitting still idling).

Also, are you calculating your mileage manually, or relying on an in-dash display? Because the display may not be entirely accurate.

I run a 4x4. I think the oil changer place put them at that psi. They said it was normal ? But i'm wondering if i should lower it on hot days, or lower them on cold days. Which is which ? That is thy question. i think they are 275/65/17

That depends. Have you changed your winter air out for summer air yet? If not, the tire pressure requirements wouldn't be the same.