How much air in the tires?? - Toyota Nation Forum : Toyota Car and Truck Forums

sirtiger · 08-23-2006, 06:54 PM

My dad bought a brand new 2006 Corolla a few months ago. He is complaining about the terrible mpg he gets. He gets about 28mpg on mix city & highway. Its not horrible but not great either.

Since he has been on a long long vaca, I've been driving his car to see what is wrong. I check for the obvious things. I think he doesn't have enuff air in the tires. It said 26 psi. which seem low.

What is the correct psi? tks.

punter · 08-23-2006, 08:09 PM

Round about 30psi is normal.

***REN69*** · 08-23-2006, 08:10 PM

yeah.. 30 to 35psi will do the job.

blueblue · 08-23-2006, 08:31 PM

Yeah that sounds a little low. Personally I put around 30- 32psi for normal street driving. I think the company recommends around 29psi.
I take it they are stock tires. Tires can affect mileage also, depending on compound, pattern and construction. Tire companies put out specific tires that will improve mileage but they dont usually handle that great.
But also consider other variables too, like is it an auto? That will affect things.
If your desperate and know a good place ( like a race prep outfit , the run of the mill crowds dont usually give a sh..t and are happy just to take your money) then check the alignment.
Also what type of fuel goes in. I found the new BP Ultra (hi-octane) fuel reduced my mileage, and I get better mileage out of 91RON... but if you're in the US then you'll have different fuel to me anyway.
You say its a new car, but it wouldnt hurt to check the plugs and make sure they arent fouled... maybe change to iridium plugs and try high performance leads... but doing that negates any fuel savings for the next 6 months!

But as a last note, be aware that cars dont usually acheive the company listed mileage anyway. You may just have got one that's at the outer end of the tolerance scale and wont work that great anyway.

Have fun!

***darksparkz*** · 08-23-2006, 08:36 PM

If you have the stock tires and wheel configuration, then use the recommended PSI on the sticker of the door jams. If you want better fuel economy, raise tire pressure by 3-5psi, a slightly rougher ride, but slightly better fuel economy.

Also, remember to measure the air pressure when the car is cooled down for at least 5 hours.

sirtiger · 08-23-2006, 09:18 PM

yes, its an auto & stock.

I appreciate the quick ans. I will up it to 30 psi & see what happens.

blueblue · 08-23-2006, 09:24 PM

One other thing simple I forgot to mention... next time its in for service, make sure they check the timing. I'm not sure about your car, but sometimes retarding the timing a little can improve economy. Of course doing that will reduce the HP a little, but hey its your call. Make sure you get out of the waiting lounge and talk to the grease monkeys or the service manager. They usually know about that tech stuff and are quite happy to help out.

daniel2002p · 08-23-2006, 11:31 PM

I always keep mine at 30 duiring the summer and 32-34 duiring the winter, but what I have found is if you add about 2 psi so making it 32 psi, my milage constantly went up by almost 2mpg, but the tires did loose a lot of traction especially in tight turns, it feels like the car just wants to fishtail... but its your call

D

freakinbox · 08-23-2006, 11:36 PM

ok. 32 is the typical pressure a shop will put in your tire. It will depend on the tires you have if you change that. As long as you don't go over the MAX psi on the tire you should be fine. If you want to take the time you can mess around with the psi. Add or drop 1 or 2 and see if you like it, repeat.

***Tercel GTS*** · 08-24-2006, 12:35 AM

Quote:

Originally Posted by blueblue

One other thing simple I forgot to mention... next time its in for service, make sure they check the timing.

Can't adjust the timing on most DIS engines without engine management.

plrsgator · 08-24-2006, 05:03 PM

30-32 is about right. Check driver's door jam & it should list the tires and manufacuturer's specs. About mileage, watch how/when you use the "Cruise". Pick a speed that eliminates down-shifting. My pickup gets 2 mpg better at 70-75 than 55-60. Since RPMs are up in the torgue range and it doesn't come out of overdrive lock-up.

GoPitt68 · 08-25-2006, 06:14 PM

Sounds like something's wrong...I have an '06 and get about 40 mpg and it's an automatic. But I do mostly highway driving. Not sure that tire pressure is the culprit for you.

07Corolla · 08-25-2006, 06:38 PM

A lot of it has to do with the way you drive. Avoid quick starts and hard stops. Adding some air to the tires will help also, but may cost more in the long run with faster tire wear.

sirtiger · 08-27-2006, 08:32 PM

Quote:

Originally Posted by GoPitt68

Sounds like something's wrong...I have an '06 and get about 40 mpg and it's an automatic. But I do mostly highway driving. Not sure that tire pressure is the culprit for you.

40 would be great...I live in NYC... home of the parking lot on the espressway

...I would be happy with 32-35mpg on mix driving.

Tango · 08-27-2006, 09:19 PM

Quote:

Originally Posted by darksparkz

If you have the stock tires and wheel configuration, then use the recommended PSI on the sticker of the door jams. If you want better fuel economy, raise tire pressure by 3-5psi, a slightly rougher ride, but slightly better fuel economy.

Also, remember to measure the air pressure when the car is cooled down for at least 5 hours.

This is good advice. I spoke to a BMW Engineer a long time ago. He stated to run tires at or just below the sidewall max pressure. It will give you much better mpg, and will protect you in the chance of an impact such as a pot hole. You tire will not likely blow out. Your car will give a slightly rougher ride, but it will be well worth it. The manual setting is for the smoothest ride. It is also the setting the tire makers like as your tire will wear faster. Another tidbit, the tire manufacturers build in a 10% overage factor in the ratings.