Timing belts improving?

changed the timing belt on 2004 Toyota Sienna at 61,000miles, as per recommendation, now the recommendations are 90,000miles, does the original mileage stay the same or follow the newer schedule, should I change at 120,000 or 150,000 since evidently belts have improved.

I don’t know if the belts are improving, but I’ve been changing my timing belt every 90,000 miles on my 1998 Civic, and every time the old belt looks just fine, like it could go another 20,000 miles.

A factory rep told me that a true lifetime timing belt could be produced but the price would be prohibitive. But then look at the motorcycle final drive belts that last 100,000 miles while transferring 100+ horsepower.

I have owned a few cars that the manual said the timing belt was to be changed at 60,000 miles and it was my responsibility, but if the same car was sold in California where the manufacturer had to guarantee the belt for 100,000 miles, the change interval moved to 105,000 miles. Pretty fishy if you ask me.

My manual originally called for 60k intervals. Some of the newer models call for 90k, same belt. But, I stick to 60k, because I love my car, and at 275k, it has loved me back. Just not worth the expensive gamble to me.

Yes. Timing belts are improving. Rubber is improving. Everything on cars is improving. I remember as a kid working at the corner service station and every month inventorying the 60 or so radiator hoses we had in stock. We stocked them because they sold. Now, I don’t stock hoses because we don’t need them. I don’t remember the last time a car came in with a blown hose. I no longer recommend changing hoses at any certain mileage because they just don’t break like they used to.

I recall seeing timing belts breaking at 70, 80, 90K miles. Now I see them go 130, 140, 150 or more before breaking.

@asemaster: “I no longer recommend changing hoses at any certain mileage because they just don’t break like they used to.”

That’s a good point. Although I had my radiator hoses replaced with the radiator, I haven’t replaced any of the other hoses on my car in its entire 15 year/235,000 mile life. I thought about it, but I never got around to it.

I did, however, have all my accessory belts replaced last time I got a new timing belt. Along with the water pump, the accessory belts get replaced with every other timing belt (every 180,000 miles).

Improving From 2004 Until The Present ?
My Older Technology 1997 Dodge Intrepid With An OHC 3.5L V-6, And A fairly Long Covoluted Timing Belt, Had A 120,000 Mile Change Interval.
I Personally Replaced It Twice In The Driveway.

I don’t know what is up with 60,000 miles, but that’s ridiculous !
I won’t buy cars with timing belts, anymore.

CSA

I took a '95 Oddysey up to 230,000 miles on the original hoses. When I took it in with a leaky hose issue, both I and the shop were kind of shocked. “Huh… a hose.” Fortunately I didn’t let it get hot enough to damage anything, and it’s still running at 260k+.

I guess I’ll plan to swap out the hoses again somewhere between 400 and 500,000?

Regarding timing belts, I try to replace them (and usually the water pump as well, as part of the “kit”) every 100k and that seems to work fine. I have never had a timing belt failure in cars that I’ve taken to 100 or 200,000 miles, including 2 Odysseys, 2 Civics, a 200SX and a Miata.

It varies from one car to the next, though, and it could be that in a newer car it makes more turns or is exposed to higher temperatures or something. If the owner’s manual says to do something and you want to preserve the car for a long time, I would do what it recommends when it recommends it.

It seems the OP changed the belt at 61K miles on the recommendation of the age of the belt, an '04 is 8 years old. Toyota mileage interval on the belt is 90K miles.

I believe Honda now says 105,000 miles or 7 years, and yes, timing belts are improving. But I would still change at 60,000 miles if the manual called for it.

Heater and rad hoses have improved dramatically. We sold our 1994 Nissan last year and it was only on its second set of hoses. The original factory ones lasted well over 100,000 miles!

Gates now makes a Kevlar timing belt for racing applications which they claim is 3x stronger than their standard belt. But because it’s for racing applications, in which they assume the owner is going to torque the heck out of the engine, they won’t make any claim as to belt life. They just say it’s 3x stronger.

I expect that, if it were used in a passenger car application, it would last significantly longer than a standard belt, but I haven’t been able to find any data on its longevity, and I don’t want to be the first guinea pig since my CRV has an inteference engine. But I wouldn’t be at all surprised if the Kevlar belt routinely went 200k in a passenger car.

I agree with @CSA. If it has a timing belt then I won’t own it.

When I had the timing belt changed on my 85 Accord at 60k it was on its last legs, with teeth about to fall off.
Belts on the 75 Civic, 81 and 88 Accords looked fine at the 60k changes.
The only time I changed hoses on my Hondas was when I replaced the leaky radiator on the 88 at 17 years and 180k miles.