New to the Forum- MPG/Tire question

Hi Everyone,

I just joined the forum after reading the great info it has for the past few days. We bought a Prius 2 years ago and love it. My wife had been wanting one for quite some time, ever since a relative got one and was telling her about the great mileage.

As one of her Christmas presents, I put some new rims and tires on it, as the original tires were getting pretty worn at 30k. Admittedly, I have not done the best job of keeping up with her car and the tire pressure. But, after reading the GY Intregity's reviews, I guess it was no great loss. Turns out, I should have done a whole lot more research before doing what I did but I talked at length about this to the guys at Tirerack and they told me I could expect a 1-2% reduction in gas mileage. I have since found out how little they know about the nature of hybrids.

I had similar rims on my 3 series BMW at the time we bought the Prius (which was white and very plain looking compared to the red or blue we really wanted) and we agreed that the car would look much better with new rims. I said that I would replace them when we got new tires...which I did.

I put on 17" ASA AR1s with 215/45-17 Goodyear Eagle ResponsEdge, an aggressive set-up but the ASAs only came in 17". (See the pics below). My wife drives the Interstate every day to work, about 40miles round trip and doesn't really do that much around town driving so I wanted something safe that performs well in the rain..

Soooo, here's the million dollar question: Just what kind of mileage hit can I expect with this set-up? She has been getting about 45 mpg with the stock set up. How much of the initial loss will be regained once the tires are broken in and how long does that usually take?

I have 30 days to drive on the tires before returning them for a full refund. The wheels cannot be returned once driven on so I will have to sell them separately if I decide against the set-up. Fortunately they fit a lot of popular car applications, including Scions and Subarus.

Thanks in advance,

John

 

Thanks, Ceric. The car certainly does drive better.

The wheels are 20lbs and the tires are 23 lbs, so that is an increase of about 12lbs a corner from stock and about 1.5 inches wider than stock. I could understand how that would negatively affect MPG, especially with a lot of in-town driving. But, as I said, she drives mostly on the Interstate and in an area that gets a good bit of rain.

I am reading about more and more Prius owners going to bigger rims so I am hoping to hear about their real-life experinces with MPG drops. Hey, it makes sense that the solar-powered concept cars are on "bicycle rims" so the increased width of the tire is bound to affect mileage to some extent.

Like many here, I'm just hoping to strike that balance between economy, better handling/safety, and appearance.

Thanks for your input.

 

Thank you, everyone! The guys at Toyota loved 'em and my friends at BMW thought they all ought to come from the factory like this to increase sales. My fellow BMW forum members just laughed and said "It must be the only modded Prius in the country. LOL" Of course, they were very wrong and it was one of them that sent me the link to PriusChat.

I live on the gulf coast, where we get some cold weather (occasionally down to 30) but it comes and goes rather quickly. Yesterday was a chilly 72 (haha) and so far, I haven't had my golf game interrupted but once.

The max TP for these tires is 44 psi. I plan to try a higher pressure than what is recommended on the Prius door label once my wife has driven it some and gotten a feel for it. I have read how many of you are using considerably higher pressures than "normal" with good success and I want to give that a shot. The low profile tires may make that a bit tough but we'll see.

So far, it looks like a 4-5 mpg hit is about right. On my drive to the airport (mix of Interstate and typical in-town driving) I got 42.7 mpg and we were averaging about 47-48. Again, the vast majority of driving has been 70 mph Interstate driving. Is that about average for hiway miles or do most of you get better than that?

Thanks again for the responses.

 

Thanks, F8L. I'm pretty sure that I am going to return the tires and market the rims. Anybody want some nice ASA AR1's???

I have now read most of the forum info on wheels/tires (which I wish I'd done beforehand), searched the Internet for decent, lightweight 16" after-market rims, and talked it over with the wife. She doesn't care that much about the appearance and is the typical "watch the screen" Prius owner.

So, I am now deciding on which brand of tires to use and what size. I may try some 195's on the stock rims as some have suggested and shoot for that balance between mileage, safety, and handling. The Goodyear ComforTreds and Michelin HydroEdges appear to be the top contenders, eh? I know some are into the GY TTs but I do not want a directional tire at this point.

Thanks again for the help.

 

My other car is a BMW 3 series coupe with GY Eagle F1 GSD3s. I have had some problems with a few sets over the years and the wheel/tire guy at my dealership (who is also a close friend, a client and has 30 years of tire experience) told me that I should avoid directional tires if at all possible. He says that he sees a lot more issues/complaints with them and the handling advantages are nominal unless you're driving them hard (e.g track/racing). But that's his opinion.

I figured on the Prius that I would go with non-directional, which rules out the TTs and the Michelin HEs. I'm leaning toward the ComforTreds in 195/60-15, which are also the closest in weight to the stock Integrities.

 

What size HEs are you running? Are they as noisy as some report or do you think that is a "placebo effect" because that is the only real complaint on TireRack's review of the HE? (They couldn't be louder than the stock GY Integrity.)

 

Thanks for the input on the directional issue. I have had directionals on most of my sports cars and did not start running into issues until I started using these low profile (225/40-18F and 255/35-18R) tires on my latest coupe. The road force values have been much higher than those of the past and he attributes part of that to the directional nature of the tires. I really don't know enough to argue with him.

I am also a Michelin fan and am just trying to digest all of the comments made on the forum. MPG is the most important thing to my wife, over looks and road noise. Although she now admits that she really likes the new rims, the 39.8 mpg she's gotten since being home ain't makin' her too happy.

I guess I'll give the Michelins a tenth look.

 

No, I am not running Michelins on my coupe. They are Goodyear Eagle F1 GSD3s. One was so out of round that you could see it with the unaided eye when the wheel was spun while the car was on the rack. Two others had outrageous road force numbers and weight requirements when balanced. This set is not quite right either. So, I am not GY's biggest fan.

The Michelin HEs are probably the right tire as we do have a fair amount of rain where we are and she spends a lot of time on the Interstate in some pretty torrential stuff at times. The road noise would concern me but it doesn't her. Hey, that's what stereo's are for.

Michelin HEs in the stock size it is! (Man, I'm glad this bit of research is over. I'm exhausted. LOL )