Hi all, I took my Prius in for the first oil change on Friday. When I got the car back the service manager told me they adjusted my tire pressure. I told him I wanted it that high (44 front 42 back). He told me that they have been instructed by Toyota to adjust the pressure during the 27 point check list. They took it down to 35 front and 33 rear. I am headed to the gas station to put it back where I had it. I also asked if they could adjust the amount of dimming in the rear view mirror. They said no so I put a piece of black felt over the sensor. Works just great (Thanks John ) Alan
Yea, it's a PITA. You'd think a service dept. would be dedicated to 'serving', but they have they're protocols and don't seem adaptable for the most part. I made a big scene last time that happened and one of the service techs took pity on me and did the pressure the way I wanted against the 'team leader's' protestations.
I suspect that such high tire pressures will translate into a bumpy ride and rattles appearing everywhere in the car. It's interesting how everyone seems to trust Toyota engineers in everything except tire pressure.
I have mine up a bit 38/36 and I do get better milage, as witness by a period when the air pressure dropped off by cold weather, as did my millage. I plan on checking the air pressure after the 5K check.
<div class='quotetop'>QUOTE(jamarimutt\";p=\"45697)</div> The engineers have nothing to do with it. It's a liability issue, plain & simple. Sticking to the norm is a common practice. And some dealers will allow you to override a standard by making them document your reqest on the work order. That officially relieves them of responsibility, then you can get what you want.
i had my oil change at 5,000 miles and i told them to leave the tire pressure alone and the tech told me that he wasnt allowed to knowingly let a car go when out of spec. i didnt push the issue because the guy is doing what he was told and afterall he didnt overfill the oil like i asked him, so i just took the car across the street to the gas station and refilled the tires.
<div class='quotetop'>QUOTE(jamarimutt\";p=\"45697)</div> The ride is slightly bumpier...I've had no complaints from passengers nor have I felt the ride to be at all uncomfortable. I guess I don't trust the "engineers" in the oil choice either as I choose to use synthetic over mineral oil. I also don't trust them as I choose to use Nu-Finish instead of trusting their engineered clear coat. I also won't trust them when I decide to change tire brands/style. This isn't about trusting them or not. It's about the individual making minor adjustments to the established 'mean' to best suit their needs/desires/etc. Some things are not easily changed. If I had the know how I might choose to use a wider range of the SOC. I might choose to use a larger..or smaller, capacity battery that's better suited to the driving conditions I have. The manufacturer's recommendations are based on an average, that doesn't make them ideal for everyone, everywhere under every concievable set of conditions. There are certainly people that should/will keep at the manufacturer's rec. tire pressures, and others that shouldn't and won't. Once you get to the service dept. level they're in a CYA mode. They'll only do what the manufacturer recommends b/c if someone has a problem and they did something outside of those and blames them they'll have to deal with that liability issue themselves. If you're happy being a lamb and following the status quo then, by all means, do so. If you don't care to investigate further, learn the facts about tire pressures, or oil types, or paint protection and just trust fully what you're told then that is your choice. Mine is to do the opposite and adjust my environment to best suit my needs and desires.
It is interesting how some expect Prius to be perfectly equipped. That's actually a very rare trait in most vehicles. Tires, tire pressure, oil, oil filter, and air filters are all prime examples. Many people think nothing of changing them afterward. Heck, some ever swap factory sparkplugs for a premium grade without any hesitation. And have you ever given brakes pads a second thought? Service personnel will usually suggest a better type and many consumers will simply agree to the change. Why should Prius be any different? What I find fascinating is who's making the comments now. It is people who wouldn't normally care. Prius raises awareness, making some question how things were done in that past. Prius even goes as far as giving a sense of empowerment to those that had not taken any initiative in the past. That's pretty cool.
Why does Toyota recommend 35/33 and does not allow their technicians to deliver a car with a different tire pressure? If it's a liabilty issue, evidently someone has determined that driving with the tires inflated above those pressures will somehow negativelly affect the car's handling or the comfort of the ride. Otherwise, they might as well not mention tire pressure at all or provide a wide range, such as front: 32-42, rear, 30-40. Overly inflated tires may give you one or two extra mpgs but you're in for a bumpy and noisy ride. Following advice from the gurus in this forum I started inflating my tires 40/38 and, sure enough, over uneven pavement the car shakes and rattles like a much older car. I don't use synthetic oil for the same reason as I don't use premium gasoline... because both are a waste of money for the Prius engine; no self-proclaimed Prius in this site has shown otherwise. Here again Toyota seems to be right. Do you gurus fill your tires with pure nitrogen?
i for one didnt notice a ride difference, but the freeways are in pretty good condition as compared to the rest of the state. i guess state assembly people are more eager to spend money in their own backyards first. of course i only went to 38/36. but i did notice a drop in mpgs though. that effect was immediate
If you feel that the ride is too uncomfortable for you and that the handling is adversely affected then I agree you should adjust the pressure to better suit you..if that happens to be the same as the manufacture's recommended then fine, if otherwise that's fine too as long as it's within tire specs. Nitrogen has been clearly shown to provide no advantages. Synthetic oil does offer certain benefits, particularly if one wants to extend engine life and extend the time b/w oil changes. Some of us chose to use synthetic b/c of possible mpg benefit (though not proven, improved engine wear, and, (most importantly to me) environmental benefit. I thoroughly researched this subject before making the decision... and it was not easily arrived at. I don't criticize anyone for chosing to use mineral...it is clearly adequate for the job and ultimately less costly (unless those using synthetic extend the time b/w oil changes). The point here is that you should do your research. If you are NOT going to research the subject and make informed decisions then you should, by all means, do what the manufacturer recommends. But just b/c they recommend it does NOT make it best for everyone under all conditions. They recommend specific tires...but what if I live in Barrow Alaska with 1 paved road that's covered with snow for more than half the year...would that be best?? The manufacturer didn't install mud flaps...should I take mine off even though they reduce spray onto my car and don't affect mpg?? We are, supposedly, thinking intelligent individuals. I thoroughly researched both the tire inflation and synthetic oil issues before chosing what I'd do. I did that even BEFORE I had my Prius and discussed the topics with intelligent informed individuals in those industries. I'm absolutely convinced it is better to use the higher pressures in the tires. I'm not entirely convinced about synthetic oil, but enough so that I recognize there is no down side (other than cost) and a potential up side and a small environmental benefit and that was enough. While we're on the subject...I considered a K&N air filter too. Deeply researched it and went back and forth for a while. Ultimately I decided that the risk of larger particles passing through the filter and some oil from the filter potentially passing into the intake was not worth it for the small performance benefit. But would you criticize someone else for making that decision? What if they chose to use a FRAM filter instead of the Toyota one? Or would you make snide remarks about them being Guru's too? This is not about being a self-proclaimed 'guru'. If you look at my comments about tire pressure I don't tell anyone the 'must' or 'should' increase their tire pressures. I tell them they should consider it and I tell them why. I've been studying and learning as much as I can both online and elsewhere about the Prius since May of 2003 on an almost daily basis. I do know a little bit about this car as I've made the effort to learn. If you chose to ignore the knowledge and information I choose to share or to make some sophomoric insult about my comments then you are free to do so. But do provide some objective informed counter arguments when you do. Please.
Just b/c this topic's got my gaul up I wanted to add more...then hopefully I'll be able to shut myself up. As for the "Toyota engineers getting it right", did they 'get it right' in choosing the 15" wheels? Apparently there was some room for flexibility since the EU version comes with 16" standard....hmmmm. Likewise the rear brakes..did they 'get it right' with the drum brakes in the US...or were they only right in the EU? If I change to 16" wheels with rear drums, then report improved handling would you then be critical b/c I didn't toe the Toyota line on that? The list goes on, the suspension is different, the bladder for the gas tank. The EV button, the mud flaps, the paint colors, the rear-view mirrors, the intelligent parking assist. To suggest that b/c that's the way it is in the US is the only way or best way and no one should change it is ludicris. It might not be best for everyone to change, but for some it is best and an informed consumer can make those decisions.
Wow What a lively debate I have started. Do I get extra points for this? BTW, I do mostly highway driving and I have always increased the pressure in my tires slightly. The important thing here is to stay within the tire manufacturers reccomendations. There is always a maximum tire pressure on the side of the tire. Usually tire manufactures recommend higher pressures for many reasons: some of them include increased weight carried in the car, sustained high speeds (who me :wink: ), etc. Alan
Hi. New to the forum. Just took delivery of a new 2004 Tideland Pearl Prius and it's everything I expected and more. Except the ride: even at the Toyota recommended inflation pressures, it rode like a buckboard on those Badyear Integrity tires. True, we have very bad patched roads in Manitoba, Canada. The dealer was very nice and offered a great trade on the Badyear tires to Michelin Harmony and it was literally a day and night difference in ride quality. For some reason my local Toyota dealer recommended 30 psi F/R. With 2,300km on the odometer, I just got back from a trip to Minneapolis. In driving rain, strong headwinds, with the cruise at 70 MPH, I got 44 MPG (Converted to U.S. gallon) on that tank of gas. In local driving, I've lost about 1.5 MPG with the Michelin Harmony tires at 30 PSI. Considering the difference in ride quality, it's worth it. I love this car!
30?? It is a max 44 PSI tire. The ride is probably better because the tires are under inflated That would also account for the decrease in mileage. Toyota spec is 35 front, 33 rear. You should at LEAST maintain the 2 PSI difference.
Manufacturer's recommended tire pressures are a compromise between rideability, longevity, handling, and with the Prius, economy. If you run at the lower end of the tire pressure, you will have more of a contact patch with the road and your stability will be better and your rideability will be softer, however, longevity and economy will suffer. Lower pressure causes the tire to heat up more, lessening the tire's life, and also cause more friction, lowering MPGs. Higher pressures put less rubber in contact with the road, decreasing friction and heat buildup, but increasing the harshness of the ride and could cause potential handling problems in adverse conditions. What you, as an owner of the vehicle, have the right to do is adjust the pressure to whatever balance you want and then accept the benefits and/or degredation that that choice causes. Just like aftermarket parts, you can add whatever you want to your vehicle, and it may or may not affect or enhance the handling of the vehicle, but that's your choice as the owner.
Good points raised. I contacted Michelin Canada and they didn't see anything wrong with the tires at 30 psi. However, I did top them up to the specification on the door jamb, and they do ride a bit stiffer. Not sure yet if there will be any change in MPG as we have cooler weather right now. Michelin claims inflating a tire to the max pressure is just as bad, if not worse, then underinflating (Harsh ride can cause loss of control, tire is more easily damaged, etc). I bought new a 1990 Toyota 4Runner with the 31 x 10.5 15 tire package, and I recall the rated pressure was 26 psi. I felt nervous running at that pressure but never had any problems. FYI the max rated psi was 50 on that tire.
